65 research outputs found
Surface critical behavior in fixed dimensions : Nonanalyticity of critical surface enhancement and massive field theory approach
The critical behavior of semi-infinite systems in fixed dimensions is
investigated theoretically. The appropriate extension of Parisi's massive field
theory approach is presented.Two-loop calculations and subsequent Pad\'e-Borel
analyses of surface critical exponents of the special and ordinary phase
transitions yield estimates in reasonable agreement with recent Monte Carlo
results. This includes the crossover exponent , for which we obtain
the values and , considerably
lower than the previous -expansion estimates.Comment: Latex with Revtex-Stylefiles, 4 page
On three dimensional bosonization
We discuss Abelian and non-Abelian three dimensional bosonization within the
path-integral framework. We present a systematic approach leading to the
construction of the bosonic action which, together with the bosonization recipe
for fermion currents, describes the original fermion system in terms of vector
bosons.Comment: 15 pages, LaTe
Current Algebra and Bosonization in Three Dimensions
We consider the fermion-boson mapping in three dimensional space-time, in the Abelian case, from the current algebra point of view. We show that in a path-integral framework one can derive a general bosonization recipe leading, in the bosonic language, to the correct equal-time current commutators of the original free fermionic theory.Facultad de Ciencias Exacta
On three dimensional bosonization
We discuss Abelian and non-Abelian three dimensional bosonization within the path-integral framework. We present a systematic approach leading to the construction of the bosonic action which, together with the bosonization recipe for fermion currents, describes the original fermion system in terms of vector bosons.Facultad de Ciencias Exacta
Duality between Topologically Massive and Self-Dual models
We show that, with the help of a general BRST symmetry, different theories in 3 dimensions can be connected through a fundamental topological field theory related to the classical limit of the Chern-Simons model.Facultad de Ciencias Exacta
Algebraic Self-Similar Renormalization in Theory of Critical Phenomena
We consider the method of self-similar renormalization for calculating
critical temperatures and critical indices. A new optimized variant of the
method for an effective summation of asymptotic series is suggested and
illustrated by several different examples. The advantage of the method is in
combining simplicity with high accuracy.Comment: 1 file, 44 pages, RevTe
On the Electric Charge of Monopoles at Finite Temperature
We calculate the electric charge at finite temperature for non-Abelian
monopoles in spontaneously broken gauge theories with a CP violating
-term. A careful treatment of dyon's gauge degrees of freedom shows
that Witten formula for the dyon charge at , ,
remains valid at .Comment: 13 pages, latex file, no figure
Chiral phase transitions: focus driven critical behavior in systems with planar and vector ordering
The fixed point that governs the critical behavior of magnets described by
the -vector chiral model under the physical values of () is
shown to be a stable focus both in two and three dimensions. Robust evidence in
favor of this conclusion is obtained within the five-loop and six-loop
renormalization-group analysis in fixed dimension. The spiral-like approach of
the chiral fixed point results in unusual crossover and near-critical regimes
that may imitate varying critical exponents seen in physical and computer
experiments.Comment: 4 pages, 5 figures. Discussion enlarge
Large-N expansion based on the Hubbard-operator path integral representation and its application to the model
In the present work we have developed a large-N expansion for the model
based on the path integral formulation for Hubbard-operators. Our large-N
expansion formulation contains diagrammatic rules, in which the propagators and
vertex are written in term of Hubbard operators. Using our large-N formulation
we have calculated, for J=0, the renormalized boson propagator. We
also have calculated the spin-spin and charge-charge correlation functions to
leading order 1/N. We have compared our diagram technique and results with the
existing ones in the literature.Comment: 6 pages, 3 figures, Phys.Rev.B (in press
Extension to order of the high-temperature expansions for the spin-1/2 Ising model on the simple-cubic and the body-centered-cubic lattices
Using a renormalized linked-cluster-expansion method, we have extended to
order the high-temperature series for the susceptibility
and the second-moment correlation length of the spin-1/2 Ising models on
the sc and the bcc lattices. A study of these expansions yields updated direct
estimates of universal parameters, such as exponents and amplitude ratios,
which characterize the critical behavior of and . Our best
estimates for the inverse critical temperatures are
and . For the
susceptibility exponent we get and for the correlation
length exponent we get .
The ratio of the critical amplitudes of above and below the critical
temperature is estimated to be . The analogous ratio for
is estimated to be . For the correction-to-scaling
amplitude ratio we obtain .Comment: Misprints corrected, 8 pages, latex, no figure
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