On the critical behaviour of the two dimensional spin XY model

1982 ◽  
Vol 60 (3) ◽  
pp. 368-372 ◽  
Author(s):  
Jos Rogiers
Keyword(s):  
Critical Point ◽  
Triangular Lattice ◽  
Second Order ◽  
Critical Behaviour ◽  
Transverse Magnetization ◽  
Xy Model ◽  
Two Dimensional ◽  
Exponential Behaviour ◽  
Transformation Methods

Transformation methods are used to analyse the series for the second order fluctuation of the transverse magnetization for the triangular and square lattices. For the triangular lattice some evidence is found for an exponential behaviour of this quantity near the critical point with a tentative estimate for the exponent [Formula: see text].

scholarly journals Periodic Solutions for a System of Difference Equations

2009 ◽  
Vol 2009 ◽  
pp. 1-9 ◽  
Author(s):  
Shugui Kang ◽  
Bao Shi
Keyword(s):  
Nonlinear Systems ◽  
Critical Point ◽  
Periodic Solutions ◽  
Difference Equations ◽  
Critical Point Theory ◽  
Existence Theorems ◽  
Point Theory ◽  
Second Order ◽  
System Of Difference Equations

This paper deals with the second-order nonlinear systems of difference equations, we obtain the existence theorems of periodic solutions. The theorems are proved by using critical point theory.

Impulsive differential inclusions via variational method

2017 ◽  
Vol 24 (3) ◽  
pp. 313-323 ◽  
Author(s):  
Mouffak Benchohra ◽  
Juan J. Nieto ◽  
Abdelghani Ouahab
Keyword(s):  
Variational Method ◽  
Critical Point ◽  
Differential Inclusion ◽  
Critical Point Theory ◽  
Differential Inclusions ◽  
Point Theory ◽  
Existence Results ◽  
Second Order ◽  
Impulsive Differential Inclusions

AbstractIn this paper, we establish several results about the existence of second-order impulsive differential inclusion with periodic conditions. By using critical point theory, several new existence results are obtained. We also provide an example in order to illustrate the main abstract results of this paper.

Second-Order Raman Spectra of Fluorites. I. Critical Point Analysis

1972 ◽  
Vol 50 (8) ◽  
pp. 849-857 ◽  
Author(s):  
N. Krishnamurthy ◽  
V. Soots
Keyword(s):  
Critical Point ◽  
Single Crystals ◽  
Raman Spectra ◽  
Brillouin Zone ◽  
Critical Points ◽  
Photon Counting ◽  
Second Order ◽  
Selection Rules ◽  
Point Analysis ◽  
Critical Point Analysis

With the use of a high-powered Ar+ laser and conventional photon counting techniques it has been possible to observe the second-order Raman spectra of single crystals of CaF2, SrF2, BaF2, and PbF2. The symmetries of the various parts of the spectra of the latter two were determined by using oriented single crystals of these two fluorides. The main features of the observed spectra have been analyzed, with the aid of group-theoretical selection rules, in terms of calculated phonon frequencies at the critical points of the Brillouin zone of these crystals.

scholarly journals Periodic Solutions of Second-Order Differential Inclusions Systems with -Laplacian

2012 ◽  
Vol 2012 ◽  
pp. 1-24
Author(s):  
Liang Zhang ◽  
Peng Zhang
Keyword(s):  
Critical Point ◽  
Periodic Solutions ◽  
Critical Point Theory ◽  
Differential Inclusions ◽  
Point Theory ◽  
Existence Results ◽  
Second Order ◽  
Nonsmooth Critical Point Theory ◽  
Nonsmooth Critical Point ◽  
Existence Of Periodic Solutions

The existence of periodic solutions for nonautonomous second-order differential inclusion systems with -Laplacian is considered. We get some existence results of periodic solutions for system, a.e. , , by using nonsmooth critical point theory. Our results generalize and improve some theorems in the literature.

scholarly journals Second-order L∞ variational problems and the ∞-polylaplacian

2020 ◽  
Vol 13 (2) ◽  
pp. 115-140 ◽  
Author(s):  
Nikos Katzourakis ◽  
Tristan Pryer
Keyword(s):  
Critical Point ◽  
Numerical Experiments ◽  
Lagrange Equation ◽  
Variational Problems ◽  
Second Order ◽  
Third Order ◽  
Fully Nonlinear ◽  
Euclidean Length ◽  
Special Cases

AbstractIn this paper we initiate the study of second-order variational problems in {L^{\infty}}, seeking to minimise the {L^{\infty}} norm of a function of the hessian. We also derive and study the respective PDE arising as the analogue of the Euler–Lagrange equation. Given {\mathrm{H}\in C^{1}(\mathbb{R}^{n\times n}_{s})}, for the functional\mathrm{E}_{\infty}(u,\mathcal{O})=\|\mathrm{H}(\mathrm{D}^{2}u)\|_{L^{\infty}% (\mathcal{O})},\quad u\in W^{2,\infty}(\Omega),\mathcal{O}\subseteq\Omega,{}the associated equation is the fully nonlinear third-order PDE\mathrm{A}^{2}_{\infty}u:=(\mathrm{H}_{X}(\mathrm{D}^{2}u))^{\otimes 3}:(% \mathrm{D}^{3}u)^{\otimes 2}=0.{}Special cases arise when {\mathrm{H}} is the Euclidean length of either the full hessian or of the Laplacian, leading to the {\infty}-polylaplacian and the {\infty}-bilaplacian respectively. We establish several results for (1) and (2), including existence of minimisers, of absolute minimisers and of “critical point” generalised solutions, proving also variational characterisations and uniqueness. We also construct explicit generalised solutions and perform numerical experiments.

Sign in / Sign up

Export Citation Format

Share Document