The Gibbs measures of a spin system on $Z^d$ with unbounded pair interactions $J_{xy} σ(x) σ(y)$ are studied. Here $\langle x, y \rangle \in E $, i.e. $x$ and $y$ are neighbors in $Z^d$. The intensities $J_{xy}$ and the spins $σ(x) , σ(y)$ are arbitrary real. To control their growth we introduce appropriate sets $J_q\subset R^E$ and $S_p\subset R^{Z^d}$ and prove that for every $J = (J_{xy}) \in J_q$: (a) the set of Gibbs measures $G_p(J)= \{μ: solves DLR, μ(S_p)=1\}$ is non-void and weakly compact; (b) each $μ\inG_p(J)$ obeys an integrability estimate, the same for all $μ$. Next we study the case where $J_q$ is equipped with a norm, with the Borel $σ$-field $B(J_q)$, and with a complete probability measure $ν$. We show that the set-valued map $J \mapsto G_p(J)$ is measurable and hence there exist measurable selections $J_q \ni J \mapsto μ(J) \in G_p(J)$, which are random Gibbs measures. We prove that the empirical distributions $N^{-1} \sum_{n=1}^N π_{Δ_n} (\cdot| J, ξ)$, obtained from the local conditional Gibbs measures $π_{Δ_n} (\cdot| J, ξ)$ and from exhausting sequences of $Δ_n \subset Z^d$, have $ν$-a.s. weak limits as $N\rightarrow +\infty$, which are random Gibbs measures. Similarly, we prove the existence of the $ν$-a.s. weak limits of the empirical metastates $N^{-1} \sum_{n=1}^N δ_{π_{Δ_n} (\cdot| J,ξ)}$, which are Aizenman-Wehr metastates. Finally, we prove the existence of the limiting thermodynamic pressure under some further conditions on $ν$.
Gibbs fields with continuous spins are studied, the underlying graphs of which can be of unbounded vertex degree and the spin-spin pair interaction potentials are random and unbounded. A high-temperature uniqueness of such fields is proved to hold under the following conditions: (a) the vertex degree is of tempered growth, i.e., controlled in a certain way; (b) the interaction potentials $W_{xy}$ are such that $\|W_{xy}\|=\sup_{σ,σ'} |W_{xy}(σ, σ')|$ are independent (for different edges $\langle x, y \rangle$), identically distributed and exponentially integrable random variables.
Gibbs random fields with unbounded spins on unbounded degree graphs
构造了对应于实值自旋系统（例如相互作用非谐振子系统）的Gibbs随机场，该系统由具有一定可和性的无界度图的顶点索引.证明了回火Gibbs随机场集是非空的弱紧的，并且服从一致指数可积性估计。在第二部分的文件中，一类图中所提到的可和性是作为一个属性的结果，凭借它的大程度的顶点位于大的距离彼此。后者是度量性质的更强版本，在[Bassalygo，L. A.和Dobrushin，R. L.（1986年）。\textrm{Uniqueness of a Gibbs field with a random potential--an elementary approach.} \textit{Theory Probab. Appl.} { \bf 31} 572- 589]。
We aim this paper to develop the classical lattice models with unbounded spin to the case of non-quadratic polynomial interaction. We demonstrate that the distinct relation between the growths of potentials leads to the uniqueness and the fast decay of correlations for Gibbs measure.
In the present paper, the Ising model with mixed spin-(1,1/2) is considered on the second order Cayley tree. A construction of splitting Gibbs measures corresponding the model is given which allows to establish the existence of the phase transition (non-uniqueness of Gibbs measures). We point out that, in the phase transition region, the considered model has three translation-invariant Gibbs measures in the ferromagnetic and anti-ferromagnetic regimes, while the classical Ising model does not possesses such Gibbs measures in the anti-ferromagnetic regime. It turns out that the considered model…
For a broad class of Gaussian disordered systems at low temperature, we show that the Gibbs measure is asymptotically localized in small neighborhoods of a small number of states. From a single argument, we obtain (i) a version of "complete" path localization for directed polymers that is not available even for exactly solvable models; and (ii) a result about the exhaustiveness of Gibbs states in spin glasses not requiring the Ghirlanda-Guerra identities.
The Abdus Salam International Center for Theoretical Physics（阿卜杜勒·萨拉姆国际理论物理中心）；University of Toronto（多伦多大学）
We consider a generic class of log-concave, possibly random, (Gibbs) measures. We prove the concentration of an infinite family of order parameters called multioverlaps. Because they completely parametrise the quenched Gibbs measure of the system, this implies a simple representation of the asymptotic Gibbs measures, as well as the decoupling of the variables in a strong sense. These results may prove themselves useful in several contexts. In particular in machine learning and high-dimensional inference, log-concave measures appear in convex empirical risk minimisation, maximum a-posteriori in…
Quantifying Gibbs measures of disordered crystals up to the solid-liquid phase transition
Center for Advanced Systems Understanding, Helmholtz Zentrum Dresden-Rossendorf（德国德累斯顿-罗斯多夫亥姆霍兹中心高级系统理解中心）；Department of Chemistry, Paderbon University（帕德博恩大学化学系）；Institute of Artificial Intelligence, TU Dresden（德累斯顿工业大学人工智能研究所）；Department of Physics, Yeshiva University（叶史瓦大学物理系）
In this note, we study the hydrodynamic limit, in the hyperbolic space-time scaling, for a one-dimensional unpinned chain of quantum harmonic oscillators with random masses. To the best of our knowledge, this is among the first examples, where one can prove the hydrodynamic limit for a quantum system rigorously. In fact, we prove that after hyperbolic rescaling of time and space the distribution of the elongation, momentum, and energy averaged under the proper Gibbs state, converges to the solution of the Euler equation. There are two main phenomena in this chain which enable us to deduce this…
Disordered systems such as spin glasses have been used extensively as models for high-dimensional random landscapes and studied from the perspective of optimization algorithms. In a recent paper by L. Addario-Berry and the second author, the continuous random energy model (CREM) was proposed as a simple toy model to study the efficiency of such algorithms. The following question was raised in that paper: what is the threshold $β_G$, at which sampling (approximately) from the Gibbs measure at inverse temperature $β$ becomes algorithmically hard? This paper is a first step towards answering this…
Splitting Gibbs Measures for a Periodic Triple Mixed-Spin Ising Model on a Cayley Tree
The United Arab Emirates University（阿联酋大学）；V.I. Romanovskiy Institute of Mathematics, Uzbekistan Academy of Sciences（乌兹别克斯坦科学院 V.I.罗曼诺夫斯基数学研究所）；Oriental University（东方大学）
Structural analysis of Gibbs states and metastates in short-range classical spin glasses: indecomposable metastates, dynamically-frozen states, and metasymmetry
