9 research outputs found
Quantum Gravity Hamiltonian for Manifolds with Boundary
In canonical quantum gravity, when space is a compact manifold with boundary
there is a Hamiltonian given by an integral over the boundary. Here we compute
the action of this `boundary Hamiltonian' on observables corresponding to open
Wilson lines in the new variables formulation of quantum gravity. In cases
where the boundary conditions fix the metric on the boundary (e.g., in the
asymptotically Minkowskian case) one can obtain a finite result, given by a
`shift operator' generating translations of the Wilson line in the direction of
its tangent vector. A similar shift operator serves as the Hamiltonian
constraint in Morales-T\'ecotl and Rovelli's work on quantum gravity coupled to
Weyl spinors. This suggests the appearance of an induced field theory of Weyl
spinors on the boundary, analogous to that considered in Carlip's work on the
statistical mechanics of the 2+1-dimensional black hole.Comment: 17 pages in LaTeX format, vastly improved versio
Critical Behavior of Dimensionally Continued Black Holes
The critical behavior of black holes in even and odd dimensional spacetimes
is studied based on Ba\~nados-Teitelboim-Zanelli (BTZ) dimensionally continued
black holes. In even dimensions it is found that asymptotically flat and anti
de-Sitter Reissner-Nordstr\"om black holes present up to two second order phase
transitions. The case of asymptotically anti-de-Sitter Schwarzschild black
holes present only one critical transition and a minimum of temperature, which
occurs at the transition. Finally, it is shown that phase transitions are
absent in odd dimensions.Comment: 21 pages in Latex format, no figures, vastly improved version to
appear in Phys. Rev.
UCRHEP-T132 Anomalous commutator corrections to sum rules
In this paper we consider the contributions of anomalous commutators to various QCD sum rules. Using a combination of the BJL limit with the operator product expansion the results are presented in terms of the vacuum condensates of gauge invariant operators. It is demonstrated that the anomalous contributions are no negligible and reconcile various apparently contradictory calculation
Research data supporting "Surface plasmons on Pd(110): An ab initio calculation"
We provide supporting dataset corresponding to the paper “Surface plasmon on Pd(110): an ab initio calculation”, by U. Muniain, R. Esteban, I. P. Chernov, J. Aizpurua and V. M. Silkin, published in Physical Review B (DOI: 10.1103/PhysRevB.103.045407). The dataset is organized in 12 binary files to extract the imaginary part of the noninteracting response function Xi0_{GG’}(q,w) (as determined by Eq. (3) in the article), for three particular q vectors in the Gamma-X direction: q = 0.0168 1/Å, q = 0.0840 1/Å and q = 0.4032 1/Å. For q = 0.0168 1/Å, the full set of data is divided into four files “Pd110_01_Ax”, where x = 1, 2, 3 and 4. We also include a FORTRAN program “Reading_Xi0_IM_01.f” that reads the response function from those four files for a range of energies, as determined in the FORTRAN program. This FORTRAN program can be used to handle the data, as stated in the program itself. For the other two q vectors, the data (four files) and the reading FORTRAN program are organized in the same way, where the number “01” in the files of the example above is replaced by “05” for q = 0.0840 1/Å and by “24” for q = 0.4032 1/Å.Peer reviewe