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0704.0909	Sara Azzali	L^2 rho form for normal coverings of fibre bundles	We define the secondary invariants L^2- eta and -rho forms for families of generalized Dirac operators on normal coverings of fibre bundles. On the covering family we assume transversally smooth spectral projections, and Novikov--Shubin invariants bigger than 3(dim B+1) to treat the large time asymptotic for general operators. In the particular case of a bundle of spin manifolds, we study the L^2- rho class in relation to the space of positive scalar curvature vertical metrics.	What is the title of this paper? arXiv:0704.0909v2 [math.GT] 5 Sep 2010L2-RHO FORM FOR NORMAL COVERINGS OF FIBRE BUNDLES SARA AZZALI Abstract. We deﬁne the secondary invariants L2-eta and -rho forms for families of generalized Dirac operators on normal coverings of ﬁbre b undles. On the cover- ing family we assume transversally s
0704.0910	Efton Park and Jody Trout	On the Nonexistence of Nontrivial Involutive n-Homomorphisms of C*-algebras	An n-homomorphism between algebras is a linear map $\phi : A \to B$ such that $\phi(a_1 ... a_n) = \phi(a_1)... \phi(a_n)$ for all elements $a_1, >..., a_n \in A.$ Every homomorphism is an n-homomorphism, for all n >= 2, but the converse is false, in general. Hejazian et al. [7] ask: Is every -preserving n-homomorphism between C-algebras continuous? We answer their question in the affirmative, but the even and odd n arguments are surprisingly disjoint. We then use these results to prove stronger ones: If n >2 is even, then $\phi$ is just an ordinary -homomorphism. If n >= 3 is odd, then $\phi$ is a difference of two orthogonal -homomorphisms. Thus, there are no nontrivial -linear n-homomorphisms between C-algebras.	What is the title of this paper? arXiv:0704.0910v3 [math.OA] 27 Sep 2007TRANSACTIONS OF THE AMERICAN MATHEMATICAL SOCIETY Volume 00, Number 0, Pages 000–000 S 0002-9947(XX)0000-0 ON THE NONEXISTENCE OF NONTRIVIAL INVOLUTIVE n-HOMOMORPHISMS OF C⋆-ALGEBRAS EFTON PARK AND JODY TROUT Abstract. Ann-homomorphism between algebras is a l
0704.0911	Debra Meloy Elmegreen (1), Bruce G. Elmegreen (2), Thomas Ferguson (1), Brendan Mullan (1,3) ((1) Vassar College, (2) IBM T.J. Watson Research Center, (3) Colgate University)	Smooth and Starburst Tidal Tails in the GEMS and GOODS Fields	GEMS and GOODS fields were examined to z~1.4 for galaxy interactions and mergers. The basic morphologies are familiar: antennae with long tidal tails, tidal dwarfs, and merged cores; M51-type galaxies with disk spirals and tidal arm companions; early-type galaxies with diffuse plumes; equal-mass grazing-collisions; and thick J-shaped tails beaded with star formation and double cores. One type is not common locally and is apparently a loose assemblage of smaller galaxies. Photometric measurements were made of the tails and clumps, and physical sizes were determined assuming photometric redshifts. Antennae tails are a factor of ~3 smaller in GEMS and GOODS systems compared to local antennae; their disks are a factor of ~2 smaller than locally. Collisions among early type galaxies generally show no fine structure in their tails, indicating that stellar debris is usually not unstable. One exception has a 5x10**9 Msun smooth red clump that could be a pure stellar condensation. Most tidal dwarfs are blue and probably form by gravitational instabilities in the gas. One tidal dwarf looks like it existed previously and was incorporated into the arm tip by tidal forces. The star-forming regions in tidal arms are 10 to 1000 times more massive than star complexes in local galaxies, although their separations are about the same. If they all form by gravitational instabilities, then the gaseous velocity dispersions in interacting galaxies have to be larger than in local galaxies by a factor of ~5 or more; the gas column densities have to be larger by the square of this factor.	What is the title of this paper? arXiv:0704.0911v1 [astro-ph] 6 Apr 2007Smooth and Starburst Tidal Tails in the GEMS and GOODS Fields Debra Meloy Elmegreen Vassar College, Dept. of Physics & Astronomy, Box 745, Pough keepsie, NY 12604; elmegreen@vassar.edu Bruce G. Elmegreen IBM Research Division, T.J. Watson Research Center, P.O
0704.0912	Martin M. Boyd, Tanya Zelevinsky, Andrew D. Ludlow, Sebastian Blatt, Thomas Zanon-Willette, Seth M. Foreman and Jun Ye	Nuclear Spin Effects in Optical Lattice Clocks	We present a detailed experimental and theoretical study of the effect of nuclear spin on the performance of optical lattice clocks. With a state-mixing theory including spin-orbit and hyperfine interactions, we describe the origin of the $^1S_0$-$^3P_0$ clock transition and the differential g-factor between the two clock states for alkaline-earth(-like) atoms, using $^{87}$Sr as an example. Clock frequency shifts due to magnetic and optical fields are discussed with an emphasis on those relating to nuclear structure. An experimental determination of the differential g-factor in $^{87}$Sr is performed and is in good agreement with theory. The magnitude of the tensor light shift on the clock states is also explored experimentally. State specific measurements with controlled nuclear spin polarization are discussed as a method to reduce the nuclear spin-related systematic effects to below 10$^{-17}$ in lattice clocks.	What is the title of this paper? arXiv:0704.0912v2 [physics.atom-ph] 10 Jul 2007Nuclear Spin Eﬀects in Optical Lattice Clocks Martin M. Boyd, Tanya Zelevinsky, Andrew D. Ludlow, Sebastian Blatt, Thomas Zanon-Willette, Seth M. Foreman, and Jun Ye JILA, National Institute of Standards and Technology and Un iversity of Colorado, Dep
0704.0913	Zhihong Lu, P. B. Visscher, and W. H. Butler	Domain wall switching: optimizing the energy landscape	It has recently been suggested that exchange spring media offer a way to increase media density without causing thermal instability (superparamagnetism), by using a hard and a soft layer coupled by exchange. Victora has suggested a figure of merit xi = 2 E_b/mu_0 m_s H_sw, the ratio of the energy barrier to that of a Stoner-Wohlfarth system with the same switching field, which is 1 for a Stoner-Wohlfarth (coherently switching) particle and 2 for an optimal two-layer composite medium. A number of theoretical approaches have been used for this problem (e.g., various numbers of coupled Stoner-Wohlfarth layers and continuum micromagnetics). In this paper we show that many of these approaches can be regarded as special cases or approximations to a variational formulation of the problem, in which the energy is minimized for fixed magnetization. The results can be easily visualized in terms of a plot of the energy as a function of magnetic moment m_z, in which both the switching field [the maximum slope of E(m_z)] and the stability (determined by the energy barrier E_b) are geometrically visible. In this formulation we can prove a rigorous limit on the figure of merit xi, which can be no higher than 4. We also show that a quadratic anistropy suggested by Suess et al comes very close to this limit.	What is the title of this paper? arXiv:0704.0913v1 [cond-mat.stat-mech] 6 Apr 2007Domain wall switching: optimizing the energy landscape Zhihong Lu MINT Center and Department of Physics and Astronomy University of Alabama, Tuscaloosa AL 35487-0209 Email: zlu@mint.ua.edu P. B. Visscher MINT Center and Department of Physics and Ast
0704.0914	Allan Greenleaf, Yaroslav Kurylev, Matti Lassas and Gunther Uhlmann	Electromagnetic wormholes via handlebody constructions	Cloaking devices are prescriptions of electrostatic, optical or electromagnetic parameter fields (conductivity $\sigma(x)$, index of refraction $n(x)$, or electric permittivity $\epsilon(x)$ and magnetic permeability $\mu(x)$) which are piecewise smooth on $\mathbb R^3$ and singular on a hypersurface $\Sigma$, and such that objects in the region enclosed by $\Sigma$ are not detectable to external observation by waves. Here, we give related constructions of invisible tunnels, which allow electromagnetic waves to pass between possibly distant points, but with only the ends of the tunnels visible to electromagnetic imaging. Effectively, these change the topology of space with respect to solutions of Maxwell's equations, corresponding to attaching a handlebody to $\mathbb R^3$. The resulting devices thus function as electromagnetic wormholes.	What is the title of this paper? arXiv:0704.0914v1 [math.AP] 6 Apr 2007Electromagnetic wormholes via handlebody constructions Allan Greenleaf, Yaroslav Kurylev, Matti Lassas and Gunther Uhlmann∗ Abstract Cloaking devices are prescriptions of electrostatic, opti cal or elec- tromagnetic parameter ﬁelds (conductivity σ(x), index of
0704.0915	S. Noda, K. Hasegawa, H. Sugime, K. Kakehi, Z. Zhang, S. Maruyama, Y. Yamaguchi	Millimeter-Thick Single-Walled Carbon Nanotube Forests: Hidden Role of Catalyst Support	A parametric study of so-called "super growth" of single-walled carbon nanotubes(SWNTs) was done by using combinatorial libraries of iron/aluminum oxide catalysts. Millimeter-thick forests of nanotubes grew within 10 min, and those grown by using catalysts with a thin Fe layer (about 0.5 nm) were SWNTs. Although nanotube forests grew under a wide range of reaction conditions such as gas composition and temperature, the window for SWNT was narrow. Fe catalysts rapidly grew nanotubes only when supported on aluminum oxide. Aluminum oxide, which is a well-known catalyst in hydrocarbon reforming, plays an essential role in enhancing the nanotube growth rates.	What is the title of this paper? Millimeter-Thick Single-Walled Carbon Nanotube Forests: Hidden Role of Catalyst Support Suguru Noda1*, Kei Hasegawa1, Hisashi Sugime1, Kazunori Kakehi1, Zhengyi Zhang2, Shigeo Maruyama2 and Yukio Yamaguchi1 1Department of Chemical System Engineering, School of Engineering, The University of Tokyo
0704.0916	A.V. Voinov, S.M. Grimes, C.R. Brune, M.J. Hornish, T.N. Massey, A. Salas	Test of nuclear level density inputs for Hauser-Feshbach model calculations	The energy spectra of neutrons, protons, and alpha-particles have been measured from the d+59Co and 3He+58Fe reactions leading to the same compound nucleus, 61$Ni. The experimental cross sections have been compared to Hauser-Feshbach model calculations using different input level density models. None of them have been found to agree with experiment. It manifests the serious problem with available level density parameterizations especially those based on neutron resonance spacings and density of discrete levels. New level densities and corresponding Fermi-gas parameters have been obtained for reaction product nuclei such as 60Ni,60Co, and 57Fe.	What is the title of this paper? arXiv:0704.0916v2 [nucl-ex] 11 Jul 2007Test of nuclear level density inputs for Hauser-Feshbach mo del calculations 1A.V. Voinov∗,1S.M. Grimes,1C.R. Brune,1M.J. Hornish,1T.N. Massey,1,2A. Salas 1Department of Physics and Astronomy, Ohio University, Athe ns, OH 45701, USA and 2Los-Alamos National L
0704.0917	Dominique Naef, Michel Mayor, Willy Benz, Francois Bouchy, Gaspare Lo Curto, Christophe Lovis, Claire Moutou, Francesco Pepe, Didier Queloz, Nuno C. Santos and Stephane Udry	The HARPS search for southern extra-solar planets. IX. Exoplanets orbiting HD 100777, HD 190647, and HD 221287	The HARPS high-resolution high-accuracy spectrograph is offered to the astronomical community since the second half of 2003. Since then, we have been using this instrument for monitoring radial velocities of a large sample of Solar-type stars (~1400 stars) in order to search for their possible low-mass companions. Amongst the goals of our survey, one is to significantly increase the number of detected extra-solar planets in a volume-limited sample to improve our knowledge of their orbital elements distributions and thus obtain better constraints for planet-formation models. In this paper, we present the HARPS radial-velocity data and orbital solutions for 3 Solar-type stars: HD 100777, HD 190647, and HD 221287. The radial-velocity data of HD 100777 is best explained by the presence of a 1.1 M_Jup planetary companion on a 384--day eccentric orbit (e=0.36). The orbital fit obtained for the slightly evolved star HD 190647 reveals the presence of a long-period (P=1038 d) 1.9 M_Jup planetary companion on a moderately eccentric orbit (e=0.18). HD 221287 is hosting a 3.1 M_Jup planet on a 456--day orbit. The shape of this orbit is not very well constrained because of our non-optimal temporal coverage and because of the presence of abnormally large residuals. We find clues for these large residuals to result from spectral line profile variations probably induced by stellar activity related processes.	What is the title of this paper? Astronomy & Astrophysics manuscript no. dnaef˙7361˙ﬁnal c ESO 2021 August 29, 2021 The HARPS search for southern extra-solar planets. IX. Exoplanets orbiting HD 100777, HD 190647, and HD 221287? D. Naef1;2, M. Mayor2, W. Benz3, F. Bouchy4, G. Lo Curto1, C. Lovis2, C. Moutou5, F. Pepe2, D. Queloz2, N
0704.0918	Seth Sullivant	Algebraic geometry of Gaussian Bayesian networks	Conditional independence models in the Gaussian case are algebraic varieties in the cone of positive definite covariance matrices. We study these varieties in the case of Bayesian networks, with a view towards generalizing the recursive factorization theorem to situations with hidden variables. In the case when the underlying graph is a tree, we show that the vanishing ideal of the model is generated by the conditional independence statements implied by graph. We also show that the ideal of any Bayesian network is homogeneous with respect to a multigrading induced by a collection of upstream random variables. This has a number of important consequences for hidden variable models. Finally, we relate the ideals of Bayesian networks to a number of classical constructions in algebraic geometry including toric degenerations of the Grassmannian, matrix Schubert varieties, and secant varieties.	What is the title of this paper? ALGEBRAIC GEOMETRY OF GAUSSIAN BAYESIAN NETWORKS SETH SULLIVANT Abstract. Conditional independence models in the Gaussian case are algebraic varieties in the cone of positive denite covariance matrices. We study these varieties in the case of Bayesian networks, with a view towards generalizing the
0704.0919	Oleksandr Zelyak, Ganpathy Murthy, Igor Rozhkov	Interactions, superconducting $T_c$, and fluctuation magnetization for two coupled dots in the crossover between the Gaussian Orthogonal and Unitary ensembles	We study a system of two quantum dots connected by a hopping bridge. Both the dots and connecting region are assumed to be in universal crossover regimes between Gaussian Orthogonal and Unitary ensembles. Using a diagrammatic approach appropriate for energy separations much larger than the level spacing we obtain the ensemble-averaged one- and two-particle Green's functions. It turns out that the diffuson and cooperon parts of the two-particle Green's function can be described by separate scaling functions. We then use this information to investigate a model interacting system in which one dot has an attractive s-wave reduced Bardeen-Cooper-Schrieffer interaction, while the other is noninteracting but subject to an orbital magnetic field. We find that the critical temperature is {\it nonmonotonic} in the flux through the second dot in a certain regime of interdot coupling. Likewise, the fluctuation magnetization above the critical temperature is also nonmonotonic in this regime, can be either diamagnetic or paramagnetic, and can be deduced from the cooperon scaling function.	What is the title of this paper? arXiv:0704.0919v1 [cond-mat.mes-hall] 6 Apr 2007Interactions, superconducting Tc, and ﬂuctuation magnetization for two coupled dots in the crossover between the Gaussian Orthogonal and Unitary ensembles Oleksandr Zelyak∗and Ganpathy Murthy† Department of Physics and Astronomy, University of Kentuc
0704.0920	L.V. Grigorenko, M.V. Zhukov	Two-proton radioactivity and three-body decay. III. Integral formulae for decay widths in a simplified semianalytical approach	Three-body decays of resonant states are studied using integral formulae for decay widths. Theoretical approach with a simplified Hamiltonian allows semianalytical treatment of the problem. The model is applied to decays of the first excited $3/2^{-}$ state of $^{17}$Ne and the $3/2^{-}$ ground state of $^{45}$Fe. The convergence of three-body hyperspherical model calculations to the exact result for widths and energy distributions are studied. The theoretical results for $^{17}$Ne and $^{45}$Fe decays are updated and uncertainties of the derived values are discussed in detail. Correlations for the decay of $^{17}$Ne $3/2^-$ state are also studied.	What is the title of this paper? arXiv:0704.0920v1 [nucl-th] 6 Apr 2007Two-proton radioactivity and three-body decay. III. Integ ral formulae for decay widths in a simpliﬁed semianalytical approach. L. V. Grigorenko1,2,3and M. V. Zhukov4 1Flerov Laboratory of Nuclear Reactions, JINR, RU-141980 Du bna, Russia 2Gesellschaft f¨ ur S
0704.0921	A. P. Balachandran, S. G. Jo	Z^0 \to 2\gamma and the Twisted Coproduct of the Poincar\'{e} Group	Yang's theorem forbids the process $Z^0 \to 2\gamma$ in any Poincar\'{e} invariant theory if photons are bosons and their two-particle states transform under the Poincar\'{e} group in the standard way (under the standard coproduct of the Poincar\'{e} group). This is an important result as it does not depend on the assumptions of quantum field theory. Recent work on noncommutative geometry requires deforming the above coproduct by the Drinfel'd twist. We prove that $Z^0 \to 2\gamma$ is forbidden for the twisted coproduct as well. This result is also independent of the assumptions of quantum field theory. As an illustration of the use of our general formulae, we further show that $Z^0 \to \nu + \nu$ is forbidden for the standard or twisted coproduct of the Poincar\'{e} group if the neutrino is massless, even if lepton number is not conserved. This is a special case of our general result that a massive particle of spin $j$ cannot decay into two identical massless particles of the same helicity if $j$ is odd, regardless of the coproduct used.	What is the title of this paper? arXiv:0704.0921v5 [hep-th] 1 Nov 2007SU-4252-849 October 27, 2018 Z0→2γand the Twisted Coproduct of the Poincar´ e Group A. P. Balachandran1 Department of Physics, Syracuse University, Syracuse, NY 1 3244-1130, USA. S. G. Jo2 Department of Physics, Kyungpook National University, Dae gu, 702-701, K
0704.0922	Quang-Cuong Pham (LPPA, College de France)	A variation of Gronwall's lemma	We prove a variation of Gronwall's lemma.	What is the title of this paper? arXiv:0704.0922v3 [math.CA] 9 Jan 2009A variation of Gronwall’s lemma Quang-Cuong Pham LPPA, Coll` ege de France Paris, France cuong.pham@normalesup.org October 23, 2018 Abstract We prove a variation of Gronwall’s lemma. The formulationandproofofthe classical Gronwall’s lemma canbefou nd in [1]. W
0704.0923	Steven J. Miller	When the Cramer-Rao Inequality provides no information	We investigate a one-parameter family of probability densities (related to the Pareto distribution, which describes many natural phenomena) where the Cramer-Rao inequality provides no information.	What is the title of this paper? arXiv:0704.0923v1 [math.ST] 6 Apr 2007WHEN THE CRAM ´ER-RAO INEQUALITY PROVIDES NO INFORMATION STEVEN J. MILLER Abstract. We investigate a one-parameter family of probability densi ties (related to the Pareto distribution, which describes many natural phenome na) where the Cram´ er-Rao inequal- it
0704.0924	Steven J. Miller	Lower order terms in the 1-level density for families of holomorphic cuspidal newforms	The Katz-Sarnak density conjecture states that, in the limit as the conductors tend to infinity, the behavior of normalized zeros near the central point of families of L-functions agree with the N -> oo scaling limits of eigenvalues near 1 of subgroups of U(N). Evidence for this has been found for many families by studying the n-level densities; for suitably restricted test functions the main terms agree with random matrix theory. In particular, all one-parameter families of elliptic curves with rank r over Q(T) and the same distribution of signs of functional equations have the same limiting behavior. We break this universality and find family dependent lower order correction terms in many cases; these lower order terms have applications ranging from excess rank to modeling the behavior of zeros near the central point, and depend on the arithmetic of the family. We derive an alternate form of the explicit formula for GL(2) L-functions which simplifies comparisons, replacing sums over powers of Satake parameters by sums of the moments of the Fourier coefficients lambda_f(p). Our formula highlights the differences that we expect to exist from families whose Fourier coefficients obey different laws (for example, we expect Sato-Tate to hold only for non-CM families of elliptic curves). Further, by the work of Rosen and Silverman we expect lower order biases to the Fourier coefficients in families of elliptic curves with rank over Q(T); these biases can be seen in our expansions. We analyze several families of elliptic curves and see different lower order corrections, depending on whether or not the family has complex multiplication, a forced torsion point, or non-zero rank over Q(T).	What is the title of this paper? arXiv:0704.0924v4 [math.NT] 14 Feb 2009LOWER ORDER TERMS IN THE 1-LEVEL DENSITY FOR FAMILIES OF HOLOMORPHIC CUSPIDAL NEWFORMS STEVENJ. MILLER ABSTRACT . The Katz-Sarnak density conjecture states that, in the lim it as the analytic conductors tend to inﬁnity, the behavior of normalized zeros near t
0704.0925	A.T. Black, E. Gomez, L.D. Turner, S. Jung, P.D. Lett	Spinor Dynamics in an Antiferromagnetic Spin-1 Condensate	We observe coherent spin oscillations in an antiferromagnetic spin-1 Bose-Einstein condensate of sodium. The variation of the spin oscillations with magnetic field shows a clear signature of nonlinearity, in agreement with theory, which also predicts anharmonic oscillations near a critical magnetic field. Measurements of the magnetic phase diagram agree with predictions made in the approximation of a single spatial mode. The oscillation period yields the best measurement to date of the sodium spin-dependent interaction coefficient, determining that the difference between the sodium spin-dependent s-wave scattering lengths $a_{f=2}-a_{f=0}$ is $2.47\pm0.27$ Bohr radii.	What is the title of this paper? arXiv:0704.0925v2 [cond-mat.other] 13 Apr 2007Spinor Dynamics in an Antiferromagnetic Spin-1 Condensate A. T. Black, E. Gomez, L. D. Turner, S. Jung, and P. D. Lett Joint Quantum Institute, University of Maryland and National Institute of Standards and Technology, Gaithersb urg, Maryland 20899 (Da
0704.0926	Q.-C. Pham, N. Tabareau, J.-J. Slotine	A Contraction Theory Approach to Stochastic Incremental Stability	We investigate the incremental stability properties of It\^o stochastic dynamical systems. Specifically, we derive a stochastic version of nonlinear contraction theory that provides a bound on the mean square distance between any two trajectories of a stochastically contracting system. This bound can be expressed as a function of the noise intensity and the contraction rate of the noise-free system. We illustrate these results in the contexts of stochastic nonlinear observers design and stochastic synchronization.	What is the title of this paper? arXiv:0704.0926v2 [math.OC] 25 Jan 2008A Contraction Theory Approach to Stochastic Incremental Stability Quang-Cuong Pham∗ LPPA, Coll` ege de France Paris, France cuong.pham@normalesup.orgNicolas Tabareau LPPA, Coll` ege de France Paris, France tabareau.nicolas@gmail.com Jean-Jacques Slotine Nonli
0704.0927	Steven J. Miller	A Symplectic Test of the L-Functions Ratios Conjecture	Recently Conrey, Farmer and Zirnbauer conjectured formulas for the averages over a family of ratios of products of shifted L-functions. Their L-functions Ratios Conjecture predicts both the main and lower order terms for many problems, ranging from n-level correlations and densities to mollifiers and moments to vanishing at the central point. There are now many results showing agreement between the main terms of number theory and random matrix theory; however, there are very few families where the lower order terms are known. These terms often depend on subtle arithmetic properties of the family, and provide a way to break the universality of behavior. The L-functions Ratios Conjecture provides a powerful and tractable way to predict these terms. We test a specific case here, that of the 1-level density for the symplectic family of quadratic Dirichlet characters arising from even fundamental discriminants d \le X. For test functions supported in (-1/3, 1/3) we calculate all the lower order terms up to size O(X^{-1/2+epsilon}) and observe perfect agreement with the conjecture (for test functions supported in (-1, 1) we show agreement up to errors of size O(X^{-epsilon}) for any epsilon). Thus for this family and suitably restricted test functions, we completely verify the Ratios Conjecture's prediction for the 1-level density.	What is the title of this paper? arXiv:0704.0927v5 [math.NT] 20 Nov 2007A SYMPLECTIC TEST OF THE L-FUNCTIONS RATIOS CONJECTURE STEVENJ. MILLER ABSTRACT . Recently Conrey, Farmer and Zirnbauer [CFZ1, CFZ2] conjec tured for- mulasfortheaveragesoverafamilyofratiosofproductsofs hiftedL-functions. Their L-functionsRatios Conjecturepre
0704.0928	Luis Anchordoqui, Haim Goldberg, Satoshi Nawata, Carlos Nunez	Cosmology from String Theory	We explore the cosmological content of Salam-Sezgin six dimensional supergravity, and find a solution to the field equations in qualitative agreement with observation of distant supernovae, primordial nucleosynthesis abundances, and recent measurements of the cosmic microwave background. The carrier of the acceleration in the present de Sitter epoch is a quintessence field slowly rolling down its exponential potential. Intrinsic to this model is a second modulus which is automatically stabilized and acts as a source of cold dark matter with a mass proportional to an exponential function of the quintessence field (hence realizing VAMP models within a String context). However, any attempt to saturate the present cold dark matter component in this manner leads to unacceptable deviations from cosmological data -- a numerical study reveals that this source can account for up to about 7% of the total cold dark matter budget. We also show that (1) the model will support a de Sitter energy in agreement with observation at the expense of a miniscule breaking of supersymmetry in the compact space; (2) variations in the fine structure constant are controlled by the stabilized modulus and are negligible; (3) ``fifth''forces are carried by the stabilized modulus and are short range; (4) the long time behavior of the model in four dimensions is that of a Robertson-Walker universe with a constant expansion rate (w = -1/3). Finally, we present a String theory background by lifting our six dimensional cosmological solution to ten dimensions.	What is the title of this paper? arXiv:0704.0928v3 [hep-ph] 26 Oct 2007Cosmology from String Theory Luis Anchordoqui,1Haim Goldberg,2Satoshi Nawata,1and Carlos Nu˜ nez3 1Department of Physics, University of Wisconsin-Milwaukee, Milwaukee, WI 53201 2Department of Physics, Northeastern University, Boston, MA 02115 3Department of Ph
0704.0929	Hyun Seok Yang	Noncommutative Electromagnetism As A Large N Gauge Theory	We map noncommutative (NC) U(1) gauge theory on R^d_C X R^{2n}_{NC} to U(N -> \infty) Yang-Mills theory on R^d_C, where R^d_C is a d-dimensional commutative spacetime while R^{2n}_{NC} is a 2n-dimensional NC space. The resulting U(N) Yang-Mills theory on R^d_C is equivalent to that obtained by the dimensional reduction of (d+2n)-dimensional U(N) Yang-Mills theory onto R^d_C. We show that the gauge-Higgs system (A_\mu,\Phi^a) in the U(N -> \infty) Yang-Mills theory on R^d_C leads to an emergent geometry in the (d+2n)-dimensional spacetime whose metric was determined by Ward a long time ago. In particular, the 10-dimensional gravity for d=4 and n=3 corresponds to the emergent geometry arising from the 4-dimensional N=4 vector multiplet in the AdS/CFT duality. We further elucidate the emergent gravity by showing that the gauge-Higgs system (A_\mu,\Phi^a) in half-BPS configurations describes self-dual Einstein gravity.	What is the title of this paper? arXiv:0704.0929v3 [hep-th] 3 Aug 2009HU-EP-07/12 arXiv:0704.0929 NoncommutativeElectromagnetismAsALarge NGaugeTheory Hyun Seok Yang∗ Institutf¨ urPhysik,HumboldtUniversit¨ atzuBerlin Newtonstraße15, D-12489Berlin, Germany ABSTRACT We map noncommutative (NC) U(1)gauge theory on IRd C×IR2n NCtoU(N→
0704.0930	Theodore Erler	Marginal Solutions for the Superstring	We construct a class of analytic solutions of WZW-type open superstring field theory describing marginal deformations of a reference D-brane background. The deformations we consider are generated by on-shell vertex operators with vanishing operator products. The superstring solution exhibits an intriguing duality with the corresponding marginal solution of the {\it bosonic} string. In particular, the superstring problem is ``dual'' to the problem of re-expressing the bosonic marginal solution in pure gauge form. This represents the first nonsingular analytic solution of open superstring field theory.	What is the title of this paper? arXiv:0704.0930v2 [hep-th] 17 Apr 2007August 14, 2018 Marginal Solutions for the Superstring Theodore Erler Harish-Chandra Research Institute Chhatnag Road, Jhunsi, Allahabad 211019, India E-mail:terler@mri.ernet.in Abstract WeconstructaclassofanalyticsolutionsofWZW-typeopensupers tringﬁeldtheoryd
0704.0931	Anna Pasquali, Frank C. van den Bosch, Hans-Walter Rix (MPIA)	The Isophotal Structure of Early-Type Galaxies in the SDSS: Dependence on AGN Activity and Environment	We study the dependence of the isophotal shape of early-type galaxies on their absolute B-band magnitude, their dynamical mass, and their nuclear activity and environment, using an unprecedented large sample of 847 early-type galaxies identified in the SDSS by Hao et al (2006). We find that the fraction of disky galaxies smoothly decreases with increasing luminosity. The large sample allows us to describe these trends accurately with tight linear relations that are statistically robust against the uncertainty in the isophotal shape measurements. There is also a host of significant correlations between the disky fraction and indicators of nuclear activity (both in the optical and in the radio) and environment (soft X-rays, group mass, group hierarchy). Our analysis shows however that these correlations can be accurately matched by assuming that the disky fraction depends only on galaxy luminosity or mass. We therefore conclude that neither the level of activity, nor group mass or group hierarchy help in better predicting the isophotal shape of early-type galaxies.	What is the title of this paper? arXiv:0704.0931v1 [astro-ph] 6 Apr 2007To appear in ApJ The Isophotal Structure of Early-Type Galaxies in the SDSS: Dependence on AGN Activity and Environment. Anna Pasquali, Frank C. van den Bosch and Hans-Walter Rix Max-Planck-Institut f¨ ur Astronomie, K¨ onigstuhl 17, D-69 117 Heidelberg, Germ
0704.0932	Xi Kang, Frank C. van den Bosch, Anna Pasquali (MPIA)	On the Origin of the Dichotomy of Early-Type Galaxies: The Role of Dry Mergers and AGN Feedback	Using a semi-analytical model for galaxy formation, combined with a large N-body simulation, we investigate the origin of the dichotomy among early-type galaxies. We find that boxy galaxies originate from mergers with a progenitor mass ratio $n < 2$ and with a combined cold gas mass fraction $F_{\rm cold} < 0.1$. Our model accurately reproduces the observed fraction of boxy systems as a function of luminosity and halo mass, for both central galaxies and satellites. After correcting for the stellar mass dependence, the properties of the last major merger of early-type galaxies are independent of their halo mass. This provides theoretical support for the conjecture of Pasquali et al (2007) that the stellar mass of an early-type galaxy is the main parameter that governs its isophotal shape. We argue that the observed dichotomy of early-type galaxies has a natural explanation within hierarchical structure formation, and does not require AGN feedback. Rather, we argue that it owes to the fact that more massive systems (i) have more massive progenitors, (ii) assemble later, and (iii) have a larger fraction of early-type progenitors. Each of these three trends causes the cold gas mass fraction of the progenitors of more massive early-types to be lower, so that their last major merger was dryer. Finally, our model predicts that (i) less than 10 percent of all early-type galaxies form in major mergers that involve two early-type progenitors, (ii) more than 95 percent of all boxy early-type galaxies with $M_* < 2 \times 10^{10} h^{-1} \Msun$ are satellite galaxies, and (iii) about 70 percent of all low mass early-types do not form a supermassive black hole binary at their last major merger. The latter may help to explain why low mass early-types have central cusps, while their massive counterparts have cores.	What is the title of this paper? arXiv:0704.0932v1 [astro-ph] 6 Apr 2007Mon. Not. R. Astron. Soc. 000, 1–13 (2000) Printed 28 August 2021 (MN L ATEX style ﬁle v1.4) On the Origin of the Dichotomy of Early-Type Galaxies: The Role of Dry Mergers and AGN Feedback X. Kang1,2⋆, Frank C. van den Bosch1, A. Pasquali1 1Max-Planck-Institu
0704.0933	Fa Wang, Ashvin Vishwanath, Yong Baek Kim	Quantum and Classical Spins on the Spatially Distorted Kagome Lattice: Applications to Volborthite	In Volborthite, spin-1/2 moments form a distorted Kagom\'e lattice, of corner sharing isosceles triangles with exchange constants $J$ on two bonds and $J'$ on the third bond. We study the properties of such spin systems, and show that despite the distortion, the lattice retains a great deal of frustration. Although sub-extensive, the classical ground state degeneracy remains very large, growing exponentially with the system perimeter. We consider degeneracy lifting by thermal and quantum fluctuations. To linear (spin wave) order, the degeneracy is found to stay intact. Two complementary approaches are therefore introduced, appropriate to low and high temperatures, which point to the same ordered pattern. In the low temperature limit, an effective chirality Hamiltonian is derived from non-linear spin waves which predicts a transition on increasing $J'/J$, from $\sqrt 3\times \sqrt 3$ type order to a new ferrimagnetic {\em striped chirality} order with a doubled unit cell. This is confirmed by a large-N approximation on the O($n$) model on this lattice. While the saddle point solution produces a line degeneracy, $O(1/n)$ corrections select the non-trivial wavevector of the striped chirality state. The quantum limit of spin 1/2 on this lattice is studied via exact small system diagonalization and compare well with experimental results at intermediate temperatures. We suggest that the very low temperature spin frozen state seen in NMR experiments may be related to the disconnected nature of classical ground states on this lattice, which leads to a prediction for NMR line shapes.	What is the title of this paper? arXiv:0704.0933v2 [cond-mat.str-el] 5 Sep 2007Quantum and Classical Spins on the Spatially Distorted Kago m´ e Lattice: Applications to volborthite Cu 3V2O7(OH) 2·2 H2O Fa Wang,1,2Ashvin Vishwanath,1,2and Yong Baek Kim3,4 1Material Sciences Division, Lawrence Berkeley Laboratori es, Berkeley, Cali
0704.0934	L.V. Grigorenko, M.V. Zhukov	Two-proton radioactivity and three-body decay. IV. Connection to quasiclassical formulation	We derive quasiclassical expressions for the three-body decay width and define the ``preexponential'' coefficients for them. The derivation is based on the integral formulae for the three-body width obtained in the semianalytical approach with simplified three-body Hamiltonian [L.V. Grigorenko and M.V.\ Zhukov, arXiv:0704.0920v1]. The model is applied to the decays of the first excited $3/2^{-}$ state of $^{17}$Ne and $3/2^{-}$ ground state of $^{45}$Fe. Various qualitative aspects of the model and relations with the other simplified approaches to the three-body decays are discussed.	What is the title of this paper? arXiv:0704.0934v1 [nucl-th] 6 Apr 2007Two-proton radioactivity and three-body decay. IV. Connec tion to quasiclassical formulation. L. V. Grigorenko1,2,3and M. V. Zhukov4 1Flerov Laboratory of Nuclear Reactions, JINR, RU-141980 Du bna, Russia 2Gesellschaft f¨ ur Schwerionenforschung mbH, Planckstr
0704.0935	Alexander Dementsov, Vladimir Privman	Percolation Modeling of Conductance of Self-Healing Composites	We explore the conductance of self-healing materials as a measure of the material integrity in the regime of the onset of the initial fatigue. Continuum effective-field modeling and lattice numerical simulations are reported. Our results illustrate the general features of the self-healing process: The onset of the material fatigue is delayed, by developing a plateau-like time-dependence of the material quality. We demonstrate that in this low-damage regime, the changes in the conductance and similar transport/response properties of the material can be used as measures of the material quality degradation.	What is the title of this paper? – 1 – Percolation Modeling of Conductance of Self-Healing Composites Alexander Dementsov and Vladimir Privman * Center for Advanced Materials Processing, and Department of Physics, Clarkson University, Potsdam, New York 13699, USA PACS: 62.20.Mk, 46.50.+a, 72.80.Tm Key Wor
0704.0936	Yuji Okawa (DESY)	Analytic solutions for marginal deformations in open superstring field theory	We extend the calculable analytic approach to marginal deformations recently developed in open bosonic string field theory to open superstring field theory formulated by Berkovits. We construct analytic solutions to all orders in the deformation parameter when operator products made of the marginal operator and the associated superconformal primary field are regular.	What is the title of this paper? arXiv:0704.0936v3 [hep-th] 4 Sep 2007arXiv:0704.0936 DESY 07-047 Analytic solutions for marginal deformations in open superstring ﬁeld theory Yuji Okawa DESY Theory Group Notkestrasse 85 22607 Hamburg, Germany yuji.okawa@desy.de Abstract We extend the calculable analytic approach to marginal defor
0704.0937	Vyacheslav Boyko, Jiri Patera and Roman Popovych	Invariants of Triangular Lie Algebras	Triangular Lie algebras are the Lie algebras which can be faithfully represented by triangular matrices of any finite size over the real/complex number field. In the paper invariants ('generalized Casimir operators') are found for three classes of Lie algebras, namely those which are either strictly or non-strictly triangular, and for so-called special upper triangular Lie algebras. Algebraic algorithm of [J. Phys. A: Math. Gen., 2006, V.39, 5749; math-ph/0602046], developed further in [J. Phys. A: Math. Theor., 2007, V.40, 113; math-ph/0606045], is used to determine the invariants. A conjecture of [J. Phys. A: Math. Gen., 2001, V.34, 9085], concerning the number of independent invariants and their form, is corroborated.	What is the title of this paper? arXiv:0704.0937v4 [math-ph] 26 Sep 2007Invariants of Triangular Lie Algebras Vyacheslav Boyko†, Jiri Patera‡and Roman Popovych†§ †Institute of Mathematics of NAS of Ukraine, 3 Tereshchenkiv s’ka Str., Kyiv-4, 01601 Ukraine E-mail: boyko@imath.kiev.ua, rop@imath.kiev.ua ‡Centre de Recherches Math´
0704.0938	Hui Wang, Kipton Barros, Harvey Gould and W. Klein	Approaching equilibrium and the distribution of clusters	We investigate the approach to stable and metastable equilibrium in Ising models using a cluster representation. The distribution of nucleation times is determined using the Metropolis algorithm and the corresponding $\phi^{4}$ model using Langevin dynamics. We find that the nucleation rate is suppressed at early times even after global variables such as the magnetization and energy have apparently reached their time independent values. The mean number of clusters whose size is comparable to the size of the nucleating droplet becomes time independent at about the same time that the nucleation rate reaches its constant value. We also find subtle structural differences between the nucleating droplets formed before and after apparent metastable equilibrium has been established.	What is the title of this paper? arXiv:0704.0938v4 [cond-mat.stat-mech] 4 Jul 2007Approaching equilibrium and the distribution of clusters Hui Wang,1Kipton Barros,2Harvey Gould,1and W. Klein2 1Department of Physics, Clark University, Worcester, MA 016 10 2Department of Physics and the Center for Computational Scie nce, Boston Uni
0704.0939	Giridhar Nandikotkur, Keith M. Jahoda, R. C. Hartman, R. Mukherjee, P. Sreekumar, M. B\"ottcher, R. M. Sambruna, and Jean H. Swank	Does the Blazar Gamma-Ray Spectrum Harden with Increasing Flux? Analysis of 9 Years of EGRET Data	The Energetic Gamma-Ray Experiment Telescope (EGRET) on the Compton Gamma-Ray Observatory (CGRO) discovered gamma-ray emission from more than 67 blazars during its 9 yr lifetime. We conducted an exhaustive search of the EGRET archives and selected all the blazars that were observed multiple times and were bright enough to enable a spectral analysis using standard power-law models. The sample consists of 18 flat-spectrum radio quasars(FSRQs), 6 low-frequency peaked BL Lac objects (LBLs) and 2 high-frequency peaked BL Lac objects (HBLs). We do not detect any clear pattern in the variation of spectral index with flux. Some of the blazars do not show any statistical evidence for spectral variability. The spectrum hardens with increasing flux in a few cases. There is also evidence for a flux-hardness anticorrelation at low fluxes in five blazars. The well-observed blazars (3C 279, 3C 273, PKS 0528+134, PKS 1622-297 PKS 0208-512) do not show any overall trend in the long-term spectral dependence on flux, but the sample shows a mixture of hard and soft states. We observed a previously unreported spectral hysteresis at weekly timescales in all three FSRQs for which data from flares lasting for ~(3-4) weeks were available. All three sources show a counterclockwise rotation, despite the widely different flux profiles. We analyze the observed spectral behavior in the context of various inverse Compton mechanisms believed to be responsible for emission in the EGRET energy range. Our analysis uses the EGRET skymaps that were regenerated to include the changes in performance during the mission.	What is the title of this paper? arXiv:0704.0939v1 [astro-ph] 6 Apr 2007Accepted for publication in ApJ Preprint typeset using L ATEX style emulateapj v. 08/22/09 DOES THE BLAZAR GAMMA-RAY SPECTRUM HARDEN WITH INCREASING F LUX? - ANALYSIS OF NINE YEARS OF EGRET DATA. Giridhar Nandikotkur1,2, Keith M. Jahoda2, R. C. Hartman2, R. M
0704.0940	Peter Orland	Glueball Masses in (2+1)-Dimensional Anisotropic Weakly-Coupled Yang-Mills Theory	The confinement problem has been solved in the anisotropic (2+1)-dimensional SU(N) Yang-Mills theory at weak coupling. In this paper, we find the low-lying spectrum for N=2. The lightest excitations are pairs of fundamental particles of the (1+1)-dimensional SU(2)XSU(2) principal chiral sigma model bound in a linear potential, with a specified matching condition where the particles overlap. This matching condition can be determined from the exactly-known S-matrix for the sigma model.	What is the title of this paper? arXiv:0704.0940v2 [hep-th] 12 Apr 2007NSF-KITP-07-57 BCCUNY-HEP/07-03 GLUEBALL MASSES IN (2+1)-DIMENSIONAL ANISOTROPIC WEAKLY-COUPLED YANG-MILLS THEORY Peter Orlanda.b.c.1 a. Kavli Institute for Theoretical Physics, The University of Califo rnia, Santa Barbara, CA 93106, U.S.A. b. Physics Program,
0704.0941	Rita Tojeiro (IfA, Edinburgh), Alan F. Heavens (IfA, Edinburgh), Raul Jimenez (UPenn), Ben Panter (IfA, Edinburgh)	Recovering galaxy star formation and metallicity histories from spectra using VESPA	We introduce VErsatile SPectral Analysis (VESPA): a new method which aims to recover robust star formation and metallicity histories from galactic spectra. VESPA uses the full spectral range to construct a galaxy history from synthetic models. We investigate the use of an adaptative parametrization grid to recover reliable star formation histories on a galaxy-by-galaxy basis. Our goal is robustness as opposed to high resolution histories, and the method is designed to return high time resolution only where the data demand it. In this paper we detail the method and we present our findings when we apply VESPA to synthetic and real Sloan Digital Sky Survey (SDSS) spectroscopic data. We show that the number of parameters that can be recovered from a spectrum depends strongly on the signal-to-noise, wavelength coverage and presence or absence of a young population. For a typical SDSS sample of galaxies, we can normally recover between 2 to 5 stellar populations. We find very good agreement between VESPA and our previous analysis of the SDSS sample with MOPED.	What is the title of this paper? arXiv:0704.0941v2 [astro-ph] 6 Aug 2007Mon. Not. R. Astron. Soc. 000, 000–000 (0000) Printed 30 August 2021 (MN L ATEX style ﬁle v2.2) Recovering galaxy star formation and metallicity historie s from spectra using VESPA R. Tojeiro⋆1, A. F. Heavens1, R. Jimenez2and B. Panter1 1Institute for Astrono
0704.0942	Laura DeMarco and Suzanne Lynch Hruska	Axiom A polynomial skew products of C^2 and their postcritical sets	A polynomial skew product of C^2 is a map of the form f(z,w) = (p(z), q(z,w)), where p and q are polynomials, such that f is regular of degree d >= 2. For polynomial maps of C, hyperbolicity is equivalent to the condition that the closure of the postcritical set is disjoint from the Julia set; further, critical points either iterate to an attracting cycle or infinity. For polynomial skew products, Jonsson (Math. Ann., 1999) established that f is Axiom A if and only if the closure of the postcritical set is disjoint from the right analog of the Julia set. Here we present the analogous conclusion: critical orbits either escape to infinity or accumulate on an attracting set. In addition, we construct new examples of Axiom A maps demonstrating various postcritical behaviors.	What is the title of this paper? arXiv:0704.0942v2 [math.DS] 19 Oct 2007AXIOM A POLYNOMIAL SKEW PRODUCTS OF C2 AND THEIR POSTCRITICAL SETS LAURA DEMARCO1AND SUZANNE LYNCH HRUSKA2 Abstract. A polynomial skew product of C2is a map of the form f(z,w) = (p(z),q(z,w)), where pandqare polynomials, such that f extends holomorphically to
0704.0943	LIGO Scientific Collaboration	Search for gravitational-wave bursts in LIGO data from the fourth science run	The fourth science run of the LIGO and GEO 600 gravitational-wave detectors, carried out in early 2005, collected data with significantly lower noise than previous science runs. We report on a search for short-duration gravitational-wave bursts with arbitrary waveform in the 64-1600 Hz frequency range appearing in all three LIGO interferometers. Signal consistency tests, data quality cuts, and auxiliary-channel vetoes are applied to reduce the rate of spurious triggers. No gravitational-wave signals are detected in 15.5 days of live observation time; we set a frequentist upper limit of 0.15 per day (at 90% confidence level) on the rate of bursts with large enough amplitudes to be detected reliably. The amplitude sensitivity of the search, characterized using Monte Carlo simulations, is several times better than that of previous searches. We also provide rough estimates of the distances at which representative supernova and binary black hole merger signals could be detected with 50% efficiency by this analysis.	What is the title of this paper? arXiv:0704.0943v3 [gr-qc] 9 Oct 2007Search for gravitational-wave bursts in LIGO data from the fourth science run B Abbott14, R Abbott14, R Adhikari14, J Agresti14, P Ajith2, B Allen2,51, R Amin18, S B Anderson14, W G Anderson51, M Arain39, M Araya14, H Armandula14, M Ashley4, S Aston38, P Aufmuth
0704.0944	Michael Kuhlen (1), J\"urg Diemand (2) and Piero Madau (2, 3) ((1) Institute for Advanced Study, Princeton, (2) UC Santa Cruz, (3) Max-Planck-Institut f\"ur Astrophysik, Garching, Germany)	GLAST and Dark Matter Substructure in the Milky Way	We discuss the possibility of GLAST detecting gamma-rays from the annihilation of neutralino dark matter in the Galactic halo. We have used "Via Lactea", currently the highest resolution simulation of Galactic cold dark matter substructure, to quantify the contribution of subhalos to the annihilation signal. We present a simulated allsky map of the expected gamma-ray counts from dark matter annihilation, assuming standard values of particle mass and cross section. In this case GLAST should be able to detect the Galactic center and several individual subhalos.	What is the title of this paper? arXiv:0704.0944v1 [astro-ph] 7 Apr 2007GLASTand DarkMatter Substructure intheMilkyWay MichaelKuhlen∗,Jürg Diemand†,∗∗andPieroMadau†,‡ ∗Schoolof NaturalScience,InstituteforAdvancedStudy,Ei nsteinLane,Princeton,NJ 08540,USA †DepartmentofAstronomyandAstrophysics,UCSantaCruz, 11 56HighStreet,SantaCruz
0704.0945	Peter McCullagh, Jim Pitman, Matthias Winkel	Gibbs fragmentation trees	We study fragmentation trees of Gibbs type. In the binary case, we identify the most general Gibbs-type fragmentation tree with Aldous' beta-splitting model, which has an extended parameter range $\beta>-2$ with respect to the ${\rm beta}(\beta+1,\beta+1)$ probability distributions on which it is based. In the multifurcating case, we show that Gibbs fragmentation trees are associated with the two-parameter Poisson--Dirichlet models for exchangeable random partitions of $\mathbb {N}$, with an extended parameter range $0\le\alpha\le1$, $\theta\ge-2\alpha$ and $\alpha<0$, $\theta =-m\alpha$, $m\in \mathbb {N}$.	What is the title of this paper? arXiv:0704.0945v2 [math.PR] 14 Nov 2008Bernoulli 14(4), 2008, 988–1002 DOI:10.3150/08-BEJ134 Gibbs fragmentation trees PETER MCCULLAGH1, JIM PITMAN2and MATTHIAS WINKEL3 1Department of Statistics, University of Chicago, 5734 Univ ersity Ave, Chicago, IL 60637, USA. E-mail:pmcc@galton.uchicago.edu 2
0704.0946	Andrei Mesinger and Steven Furlanetto	Efficient Simulations of Early Structure Formation and Reionization	We present a method to construct semi-numerical ``simulations'', which can efficiently generate realizations of halo distributions and ionization maps at high redshifts. Our procedure combines an excursion-set approach with first-order Lagrangian perturbation theory and operates directly on the linear density and velocity fields. As such, the achievable dynamic range with our algorithm surpasses the current practical limit of N-body codes by orders of magnitude. This is particularly significant in studies of reionization, where the dynamic range is the principal limiting factor. We test our halo-finding and HII bubble-finding algorithms independently against N-body simulations with radiative transfer and obtain excellent agreement. We compute the size distributions of ionized and neutral regions in our maps. We find even larger ionized bubbles than do purely analytic models at the same volume-weighted mean hydrogen neutral fraction. We also generate maps and power spectra of 21-cm brightness temperature fluctuations, which for the first time include corrections due to gas bulk velocities. We find that velocities widen the tails of the temperature distributions and increase small-scale power, though these effects quickly diminish as reionization progresses. We also include some preliminary results from a simulation run with the largest dynamic range to date: a 250 Mpc box that resolves halos with masses M >~ 2.2 x10^8 M_sun. We show that accurately modeling the late stages of reionization requires such large scales. The speed and dynamic range provided by our semi-numerical approach will be extremely useful in the modeling of early structure formation and reionization.	What is the title of this paper? arXiv:0704.0946v1 [astro-ph] 9 Apr 2007Submitted to the ApJ Preprint typeset using L ATEX style emulateapj v. 6/22/04 EFFICIENT SIMULATIONS OF EARLY STRUCTURE FORMATION AND REI ONIZATION Andrei Mesinger & Steven Furlanetto Yale Center for Astronomy and Astrophysics, Yale Universit y, New Haven, CT
0704.0947	Satoki Matsushita, Sebastien Muller, Jeremy Lim (ASIAA)	Jet-disturbed molecular gas near the Seyfert 2 nucleus in M51	Previous molecular gas observations at arcsecond-scale resolution of the Seyfert 2 galaxy M51 suggest the presence of a dense circumnuclear rotating disk, which may be the reservoir for fueling the active nucleus and obscures it from direct view in the optical. However, our recent interferometric CO(3-2) observations show a hint of a velocity gradient perpendicular to the rotating disk, which suggests a more complex structure than previously thought. To image the putative circumnuclear molecular gas disk at sub-arcsecond resolution to better understand both the spatial distribution and kinematics of the molecular gas. We carried out CO(2-1) and CO(1-0) line observations of the nuclear region of M51 with the new A configuration of the IRAM Plateau de Bure Interferometer, yielding a spatial resolution lower than 15 pc. The high resolution images show no clear evidence of a disk, aligned nearly east-west and perpendicular to the radio jet axis, as suggested by previous observations, but show two separate features located on the eastern and western sides of the nucleus. The western feature shows an elongated structure along the jet and a good velocity correspondence with optical emission lines associated with the jet, suggesting that this feature is a jet-entrained gas. The eastern feature is elongated nearly east-west ending around the nucleus. A velocity gradient appears in the same direction with increasingly blueshifted velocities near the nucleus. This velocity gradient is in the opposite sense of that previously inferred for the putative circumnuclear disk. Possible explanations for the observed molecular gas distribution and kinematics are that a rotating gas disk disturbed by the jet, gas streaming toward the nucleus, or a ring with another smaller counter- or Keplarian-rotating gas disk inside.	What is the title of this paper? arXiv:0704.0947v1 [astro-ph] 9 Apr 2007Astronomy & Astrophysics manuscript no. m51pdbi-main c/circlecopyrtESO 2018 October 28, 2018 Letter to the Editor Jet-disturbed molecular gas near the Seyfert 2 nucleus in M5 1 S. Matsushita, S. Muller, and J. Lim Academia Sinica, Institute of Astronomy and A
0704.0948	H. A. Sheets, J. R. Thorstensen, C. J. Peters, A. B. Kapusta and C. J. Taylor	Spectroscopy of Nine Cataclysmic Variable Stars	We present optical spectroscopy of nine cataclysmic binary stars, mostly dwarf novae, obtained primarily to determine orbital periods Porb. The stars and their periods are LX And, 0.1509743(5) d; CZ Aql, 0.2005(6) d; LU Cam, 0.1499686(4) d; GZ Cnc, 0.0881(4) d; V632 Cyg, 0.06377(8) d; V1006 Cyg, 0.09903(9) d; BF Eri, 0.2708804(4) d; BI Ori, 0.1915(5) d; and FO Per, for which Porb is either 0.1467(4) or 0.1719(5) d. Several of the stars proved to be especially interesting. In BF Eri, we detect the absorption spectrum of a secondary star of spectral type K3 +- 1 subclass, which leads to a distance estimate of approximately 1 kpc. However, BF Eri has a large proper motion (100 mas/yr), and we have a preliminary parallax measurement that confirms the large proper motion and yields only an upper limit for the parallax. BF Eri's space velocity is evidently large, and it appears to belong to the halo population. In CZ Aql, the emission lines have strong wings that move with large velocity amplitude, suggesting a magnetically-channeled accretion flow. The orbital period of V1006 Cyg places it squarely within the 2- to 3-hour "gap" in the distribution of cataclysmic binary orbital periods.	What is the title of this paper? arXiv:0704.0948v1 [astro-ph] 6 Apr 2007Spectroscopy of Nine Cataclysmic Variable Stars1 Holly A. Sheets, John R. Thorstensen, Christopher J. Peters , and Ann B. Kapusta Department of Physics and Astronomy 6127 Wilder Laboratory, Dartmouth College Hanover, NH 03755-3528; h.a.sheets@dartmouth.edu Cy