Radion effective potential in brane gas cosmology

Abstract

We consider a cosmological solution which can explain anisotropic evolution of spatial dimensions and the stabilization of extra dimensions in brane gas formalism. We evaluate the effective potentials, induced by brane gas, bulk flux and supergravity particles, which govern the sizes of the observed three and the extra dimensions. It is possible that the wrapped internal volume can oscillate between two turning points or sit at the minimum of the potential while the unwrapped three dimensional volume can expand monotonically. Including the supergravity particles makes the effective potential steeper as the internal volume shrinks.

Persistent current in a 2D Josephson junction array wrapped around a cylinder

“…In this letter we are taking a different approach. When the dynamics of the 2D JJ array is dominated by capacitances of superconducting islands its T = 0 quantum statistical mechanics is equivalent [1,10,15,28,29] to the statistical mechanics of the classical xy spin system in 2+1 dimensions at the effective temperature T * = √ 2JU, with J being the Josephson energy of the junction and U being the charging energy of the superconducting island. The advantage of such a mapping is its suitability for large-scale Monte Carlo (MC) studies.…”

“…Positional disorder in a planar JJ array is known to give rise to random phases when the array is placed in the transverse magnetic field [30]. The resulting "gauge" or "Bose" glass has been intensively studied by analytical [31][32][33][34] and numerical [29,35,36] methods. Phase disorder has been found to have a significant effect on the SIT.…”

“…( 1). In the models of planar JJ arrays such random phase can be generated by the positional disorder in the 2D lattice of Josephson junctions in the presence of the transverse magnetic field [29,30,[32][33][34][35][36]. In our case of a JJ array wrapped around a cylinder, random phases can be generated due to, e.g., anomalous Josephson effect in the presence of magnetic moments [37,38].…”