1,057 research outputs found
"Soft power" as an instrument for external political influence of the South Korea
An alternative approach to exercising political influence through "soft power" by South Korea is viewed. Instruments used by Korean diplomacy in its pursuit of its goals are described
-point free energy distribution function in one dimensional random directed polymers
Explicit expression for the -point free energy distribution function in
one dimensional directed polymers in a random potential is derived in terms of
the Bethe ansatz replica technique. The obtained result is equivalent to the
one derived earlier by Prolhac and Spohn [J. Stat. Mech., 2011, P03020].Comment: 10 pages, 1 figur
Stability of solutions of the Sherrington-Kirkpatrick model with respect to replications of the phase space
We use real replicas within the Thouless, Anderson and Palmer construction to
investigate stability of solutions with respect to uniform scalings in the
phase space of the Sherrington-Kirkpatrick model. We show that the demand of
homogeneity of thermodynamic potentials leads in a natural way to a
thermodynamically dependent ultrametric hierarchy of order parameters. The
derived hierarchical mean-field equations appear equivalent to the discrete
Parisi RSB scheme. The number of hierarchical levels in the construction is
fixed by the global thermodynamic homogeneity expressed as generalized de
Almeida Thouless conditions. A physical interpretation of a hierarchical
structure of the order parameters is gained.Comment: REVTeX4, 22 pages, second extended version to be published in Phys.
Rev.
Critical behavior of disordered systems with replica symmetry breaking
A field-theoretic description of the critical behavior of weakly disordered
systems with a -component order parameter is given. For systems of an
arbitrary dimension in the range from three to four, a renormalization group
analysis of the effective replica Hamiltonian of the model with an interaction
potential without replica symmetry is given in the two-loop approximation. For
the case of the one-step replica symmetry breaking, fixed points of the
renormalization group equations are found using the Pade-Borel summing
technique. For every value , the threshold dimensions of the system that
separate the regions of different types of the critical behavior are found by
analyzing those fixed points. Specific features of the critical behavior
determined by the replica symmetry breaking are described. The results are
compared with those obtained by the -expansion and the scope of the
method applicability is determined.Comment: 18 pages, 2 figure
Replica Symmetry Breaking and the Renormalization Group Theory of the Weakly Disordered Ferromagnet
We study the critical properties of the weakly disordered -component
ferromagnet in terms of the renormalization group (RG) theory generalized to
take into account the replica symmetry breaking (RSB) effects coming from the
multiple local minima solutions of the mean-field equations. It is shown that
for the traditional RG flows at dimensions , which are
usually considered as describing the disorder-induced universal critical
behavior, are unstable with respect to the RSB potentials as found in spin
glasses. It is demonstrated that for a general type of the Parisi RSB
structures there exists no stable fixed points, and the RG flows lead to the
{\it strong coupling regime} at the finite scale , where
is the small parameter describing the disorder. The physical concequences
of the obtained RG solutions are discussed. In particular, we argue, that
discovered RSB strong coupling phenomena indicate on the onset of a new spin
glass type critical behaviour in the temperature interval near . Possible relevance of the considered RSB effects for
the Griffith phase is also discussed.Comment: 32 pages, Late
Cooperative behavior of qutrits with dipole-dipole interactions
We have identified a class of many body problems with analytic solution
beyond the mean-field approximation. This is the case where each body can be
considered as an element of an assembly of interacting particles that are
translationally frozen multi-level quantum systems and that do not change
significantly their initial quantum states during the evolution. In contrast,
the entangled collective state of the assembly experiences an appreciable
change. We apply this approach to interacting three-level systems.Comment: 5 pages, 3 figures. Minor correction
Logarithmic Operators in Conformal Field Theory
Conformal field theories with correlation functions which have logarithmic
singularities are considered. It is shown that those singularities imply the
existence of additional operators in the theory which together with ordinary
primary operators form the basis of the Jordan cell for the operator .
An example of the field theory possessing such correlation functions is given.Comment: 13 pages, plain TEX, PUPT-1391 (minor changes and the appendix with
additional calculations is added
Negative response to an excessive bias by a mixed population of voters
We study an outcome of a vote in a population of voters exposed to an
externally applied bias in favour of one of two potential candidates. The
population consists of ordinary individuals, that are in majority and tend to
align their opinion with the external bias, and some number of contrarians ---
individuals who are always hostile to the bias but are not in a conflict with
ordinary voters. The voters interact among themselves, all with all, trying to
find an opinion reached by the community as a whole. We demonstrate that for a
sufficiently weak external bias, the opinion of ordinary individuals is always
decisive and the outcome of the vote is in favour of the preferential
candidate. On the contrary, for an excessively strong bias, the contrarians
dominate in the population's opinion, producing overall a negative response to
the imposed bias. We also show that for sufficiently strong interactions within
the community, either of two subgroups can abruptly change an opinion of the
other group.Comment: 11 pages, 6 figure
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