arXiv subjects

Dardo Piriz

Publications and source records attributed to Dardo Piriz.

3 recordsLinked to original sources

arXiv1997

Effective operators in Supersymmetry

We consider a low-energy supersymmetric scenario in which the effects of heavy supersymmetric interactions are included in a model-independent manner through a series of supersymmetric SU(3)_C*SU(2)_L*U(1)_Y invariant operators; we explicitly construct all such operators of dimension less or equal than 6. From this set, those operators generated at tree level by the underlying theory are isolated since under weak coupling conditions they are expected to provide the largest effects in low-energy processes. Potential deviations from low energy predictions in process such as proton decay, neutrinoless double-beta decay and flavor changing neutral currents are analyzed as illustrations of the method.

hep-ph↗

arXiv1995

Critical Behavior of Dimensionally Continued Black Holes

The critical behavior of black holes in even and odd dimensional spacetimes is studied based on Bañados-Teitelboim-Zanelli (BTZ) dimensionally continued black holes. In even dimensions it is found that asymptotically flat and anti de-Sitter Reissner-Nordström 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.

gr-qc↗

arXiv1995

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-Técotl 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.

gr-qc↗