Existence, Regularity, and Properties of Generalized Apparent Horizons

We prove a conjecture of Tom Ilmanen's and Hubert Bray's regarding the existence of the outermost generalized apparent horizon in an initial data set and that it is outer area minimizing.Comment: 16 pages, thoroughly revised, no major changes, to appear in Comm. Math. Phy

Nonadiabatic Approach to Spin-Peierls Transitions via Flow Equations

The validity of the adiabatic approach to spin-Peierls transitions is assessed. An alternative approach is developed which maps the initial magneto-elastic problem to an effective magnetic problem only. Thus the equivalence of magneto-elastic solitons and magnetic spinons is shown. No soft phonon is required for the transition. Temperature dependent couplings are predicted in accordance with the analysis of experimental data.Comment: Latex, 4 pages, Phys. Rev. B, Rap. Comm. in press final version containing some clarification

Spin liquid behaviour in Jeff=1/2 triangular lattice Ba3IrTi2O9

Ba3IrTi2O9 crystallizes in a hexagonal structure consisting of a layered triangular arrangement of Ir4+ (Jeff=1/2). Magnetic susceptibility and heat capacity data show no magnetic ordering down to 0.35K inspite of a strong magnetic coupling as evidenced by a large Curie-Weiss temperature=-130K. The magnetic heat capacity follows a power law at low temperature. Our measurements suggest that Ba3IrTi2O9 is a 5d, Ir-based (Jeff=1/2), quantum spin liquid on a 2D triangular lattice.Comment: 10 pages including supplemental material, to be published in Phys. Rev. B (Rapid Comm.

Reissner-Nordstrom-like solutions of the SU(2) Einstein-Yang/Mills (EYM) equations

In this paper we study a new type of solution of the spherically symmetric, Einstein-Yang/Mills (EYM) equations with SU(2) gauge group. These solutions are well-behaved in the far-field, and have a Reissner-Nordstrom type essential singularity at the origin. These solutions display some novel features which are not present in particle-like, or black-hole solutions. Any spherically symmetric solution to the EYM equations, defined in the far-field, is either a particle-like solution, a black-hole solution, or one of these RNL solutions.Comment: 5 pages, latex, no figures, Submitted to Comm. Math. Phys. January 15, 199

Noether current from the surface term of gravitational action, Virasoro algebra and horizon entropy

We describe a simple way of obtaining horizon entropy using the approach based on the Virasoro algebra and central charge. We show that the Virasoro algebra defined by the Noether currents corresponding to the surface term of gravitational action, for the diffeomorphisms which leave the horizon structure unaltered, has a central extension that directly leads to the horizon entropy. In this approach there are no ambiguities in the calculation of the central charge. We explain why this approach is physically well motivated and could provide greater insight into the nature of horizon entropy.Comment: v2: a comment added; accepted in PRD (Rapid Comm.

A new proof of the analyticity of the electronic density of molecules

We give a new, short proof of the regularity away from the nuclei of the electronic density of a molecule obtained in [1,2]. The new argument is based on the regularity properties of the Coulomb interactions underlined in [3,4] and on well-known elliptic technics. [1] S. Fournais, M. Hoffmann-Ostenhof, T. Hoffmann-Ostenhof, T. Oe stergaard Soerensen: The electron density is smooth away from the nuclei. Comm. Math. Phys. 228, no. 3 (2002), 401-415. [2] S. Fournais, M. Hoffmann-Ostenhof, T. Hoffmann-Ostenhof, T. Oestergaard Soerensen: Analyticity of the density of electronic wave functions. Ark. Mat. 42, no. 1 (2004), 87-106. [3] W. Hunziker: Distortion analyticity and molecular resonances curves. Ann. Inst. H. Poincar\'e, s. A, t. 45, no 4, 339-358 (1986). [4] M. Klein, A. Martinez, R. Seiler, X.P. Wang: On the Born-Oppenheimer expansion for polyatomic molecules. Comm. Math. Phys. 143, no. 3, 607-639 (1992). The paper is published in Letters in Mathematical Physics 93, number 1, pp. 73-83, 2010. The original publication is available at " www.springerlink.com "

Correction to the known distribution of Prionus (Homaesthesis) simplex (Casey) (Coleoptera, Cerambycidae)

Prionus (Homaesthesis) simplex (Casey) was described (Casey, 1912:253) from one male specimen from Kansas with no further data. The specimen is in the United States National Museum and is illustrated by Chemsak (1996). Alexander (1958) reported P. simplex from two locations in Craig County, Oklahoma. Alexander's paper appears to be the basis for two localities shown in northeastern Oklahoma on the distribution maps given by Linsley (1962) and Chemsak (1996). The one locality shown in central Kansas on the map by Chemsak (1996) represents just a "state record" and not a specific collecting record (J. Beier!, Editor of Wolfs garden Books, pers. comm.