Results 61 to 70 of about 95 (95)

Exact multicritical behaviour of the Potts model

Journal of Physics A: Mathematical and General, 1993
A two-dimensional q-state Potts model with vacancies and four-spin interactions is studied. The parameter space of the model contains a critical and a tricritical manifold. Moreover for 0 less-than-or-equal-to q less-than-or-equal-to 9/4 a multicritical point is found which is the locus where the tricritical transition changes from first- to second ...
NIENHUIS, B, WARNAAR, SO, BLOTE, HWJ
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Multicritical two-dimensional vertex models

Physical Review A, 1992
We study the multicritical behavior of a class of two-dimensional ice-type vertex models on different lattices using renormalization-group theory. The models are classified by an integer m, with m=2 corresponding to the known square lattice case. For m>2, the specific-heat exponent is a=(m-2)/(m-1) with an upper critical dimensional confluent (lnt) 1/2
, Bhattacharjee, , Rajasekaran
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Multicritical behavior in ferroelectrics

Phase Transitions, 1999
Abstract Solid state systems exhibit besides usual second order phase transitions a rich variety of multicritical phenomena like Lifshitz points (or lines), tricritical points (or lines) and even tricritical Lifshitz points. Realizations of such points are numerous and were also verified in the family of ferroelectrics of the type (PbySn1y)2P2(SexS1-x ...
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MULTICRITICALITY IN STABILIZED 2D QUANTUM GRAVITY

Modern Physics Letters A, 1992
We study the simplest perturbation of the matrix model for pure gravity susceptible of reaching the k=3 multicritical point in the framework of the stochastic stabilization of 2D quantum gravity. We show the existence of a line of points in the phase diagram with the genuine critical behavior of the k=2 theory.
Diego, Oscar, González, José
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Generalized Penner models and multicritical behavior

Physical Review D, 1992
Summary: We are interested in the critical behavior of generalized Penner models at \(t\sim-1+\mu/N\), where the topological expansion for the free energy develops logarithmic singularities: \(\Gamma\sim-(\chi_0\mu^2\ln\mu+\chi_1\ln\mu+\cdots)\).
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On the type of multicritical point in NH4Cl

Solid State Communications, 1978
Abstract The temperature dependence of the tensor component d14 of the nonlinear quadratic susceptibility, measured at atmospheric pressure across the order-disorder phase transition in NH4Cl, was fitted to different expressions derived from the classical Landau theory for discontinuous phase transitions. These expressions correspond to multicritical
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Multicriticality: A Theoretical Introduction

1984
To understand multicriticality the first step is to understand ordinary critical behavior and, in particular, the theory of scaling. Ferromagnetic criticality provides the simplest example whichsuffices to define the critical exponents α,s,γ, etc.; the concept of universality classes depending on spatial dimensionality, d, and spin dimensionality, n ...
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Multicriticality in smectic liquid crystals

Journal of Non-Crystalline Solids, 2012
Abstract A phenomenological model permitting a unified description of different types of smectic liquid crystalline phases including the hexatic-B phase has been developed. The model describes five different liquid crystalline phases: nematic (N), smectic-A (SmA), smectic-C (SmC), hexatic-B (HexB) and smectic-E (SmE). We observe various multicritical
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Multicritical phenomena in liquid crystals

Journal de Chimie Physique, 1983
A detailed review is given of the progress that has been made toward the understanding of the Nematic-Smectic A identical point and the Nematic-Smectic A-Smectic C multicritical point. Other known or hypothetical liquid crystal multicritical points are reviewed briefly.
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Multicritical Points in Incommensurate Systems

1984
Since Hornreich et al1 introduced the concept of a Lifshitz point — i. e. a triple point in the Pressure-Temperature phase diagram, separating two lines of continuous transitions to ferromagnetic and helicoidal phases — a large number of theoretical studies have discussed the symmetry and critical properties of this multicritical point2–5. Experimental
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