14,120 research outputs found
Meromorphic solutions of recurrence relations and DRA method for multicomponent master integrals
We formulate a method to find the meromorphic solutions of higher-order
recurrence relations in the form of the sum over poles with coefficients
defined recursively. Several explicit examples of the application of this
technique are given. The main advantage of the described approach is that the
analytical properties of the solutions are very clear (the position of poles is
explicit, the behavior at infinity can be easily determined). These are exactly
the properties that are required for the application of the multiloop
calculation method based on dimensional recurrence relations and analyticity
(the DRA method).Comment: 20 pages, minor change
Total Born cross section of -pair production in relativistic ion collisions from differential equations
We apply the differential equation method to the calculation of the total
Born cross section of the process . We obtain explicit
expression for the cross section exact in the relative velocity of the nuclei.Comment: 5 pages, 2 figures, ancillary file MastersExpansion.m attached to
submissio
Partition function zeros at first-order phase transitions: Pirogov-Sinai theory
This paper is a continuation of our previous analysis [BBCKK] of partition
functions zeros in models with first-order phase transitions and periodic
boundary conditions. Here it is shown that the assumptions under which the
results of [BBCKK] were established are satisfied by a large class of lattice
models. These models are characterized by two basic properties: The existence
of only a finite number of ground states and the availability of an appropriate
contour representation. This setting includes, for instance, the Ising, Potts
and Blume-Capel models at low temperatures. The combined results of [BBCKK] and
the present paper provide complete control of the zeros of the partition
function with periodic boundary conditions for all models in the above class.Comment: 46 pages, 2 figs; continuation of math-ph/0304007 and
math-ph/0004003, to appear in J. Statist. Phys. (special issue dedicated to
Elliott Lieb
Interacting topological phases in multiband nanowires
We show that semiconductor nanowires coupled to an s-wave superconductor
provide a playground to study effects of interactions between different
topological superconducting phases supporting Majorana zero-energy modes. We
consider quasi-one dimensional system where the topological phases emerge from
different transverse subbands in the nanowire. In a certain parameter space, we
show that there is a multicritical point in the phase diagram where the
low-energy theory is equivalent to the one describing two coupled Majorana
chains. We study effect of interactions as well as symmetry-breaking
perturbations on the topological phase diagram in the vicinity of this
multicritical point. Our results shed light on the stability of the topological
phase around the multicritical point and have important implications for the
experiments on Majorana nanowires.Comment: 8 pages, 2 figures; final version to appear in PR
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