arXiv subjects

Nami F. Svaiter

Publications and source records attributed to Nami F. Svaiter.

3 recordsLinked to original sources

arXiv2025

Analog model for Euclidean wormholes: Bose-Einstein condensate with dirty surfaces

We study a Bose-Einstein condensate under the effects of the non-condensate atomic cloud. We model the resulting linear interaction of the condensate with the atomic gas as a quenched disorder. Using the distributional zeta function method, we obtain a representation for the quenched free energy as a series of integral moments of the partition function. Assuming that the Bose-Einstein condensate is confined between two planar surfaces, we show that random surface fields generate non-local terms in the effective action. The non-local effects in this condensed matter system define an analog model of a Euclidean wormhole. The leading contribution of the non-local interactions to the Casimir pressure is obtained.

gr-qc↗

arXiv2020

Directed Polymers and Interfaces in Disordered Media

We consider field theory formulation for directed polymers and interfaces in the presence of quenched disorder. We write a series representation for the averaged free energy, where all the integer moments of the partition function of the model contribute. The structure of field space is analysed for polymers and interfaces at finite temperature using the saddle-point equations derived from each integer moments of the partition function. For the case of an interface we obtain the wandering exponent $ξ= (4-d)/2$, also obtained by the conventional replica method for the replica symmetric scenario.

cond-mat.stat-mech↗

arXiv2020

Functional equations for regularized zeta-functions and diffusion processes

We discuss modifications in the integral representation of the Riemann zeta-function that lead to generalizations of the Riemann functional equation that preserves the symmetry $s\to (1-s)$ in the critical strip. By modifying one integral representation of the zeta-function with a cut-off that does exhibit the symmetry $x\mapsto 1/x$, we obtain a generalized functional equation involving Bessel functions of second kind. Next, with another cut-off that does exhibit the same symmetry, we obtain a generalization for the functional equation involving only one Bessel function of second kind. Some connection between one regularized zeta-function and the Laplace transform of the heat kernel for the Euclidean and hyperbolic space is discussed.

math-ph↗