Comment on a solution of Altarelli Parisi equations

We show that the assumptions of factorizability of the structure functionF(x, t) inx andt and the equality oft evolution of the singlet and gluon distributions are not necessary to obtain the approximate solutions of Altarelli-Parisi equations derived by us recently.     

The Maslov class of some Legendre submanifolds

In the paper, by using a differential-geometric machinery, one computes the Maslov class for: a) Legendre curves on S³, with respect to any one of the three classical contact forms of S³; b) Legendre submanifolds for the classical contact structure of the cotangent unit spheres bundles of a Riemannian manifold N. In case b), and if N is flat, the Maslov class is determined by the mean curvature vector, and it vanishes if the Legendre submanifold is minimal.     

Finite Size Corrections to the Parisi Overlap Function in the GREM

We investigate the effects of finite size corrections on the overlap probabilities in the Generalized Random Energy Model in two situations where replica symmetry is broken in the thermodynamic limit. Our calculations do not use replicas, but shed some light on what the replica method should give for finite size corrections. In the gradual freezing situation, which is known to exhibit full replica symmetry breaking, we show that the finite size corrections lead to a modification of the simple relations between the sample averages of the overlaps \( Y_k \) between k configurations predicted by replica theory. This can be interpreted as fluctuations in the replica block size with a negative variance. The mechanism is similar to the one we found recently in the random energy model in Derrida and Mottishaw (J Stat Mech 2015(1): P01021, 2015). We also consider a simultaneous freezing situation, which is known to exhibit one step replica symmetry breaking. We show that finite size corrections lead to full replica symmetry breaking and give a more complete derivation of the results presented in Derrida and Mottishaw (Europhys Lett 115(4): 40005, 2016) for the directed polymer on a tree.     

On the explicit construction of Parisi landscapes in finite dimensional Euclidean spaces

AnN-dimensional Gaussian landscape with multiscale translation-invariant logarithmic correlations has been constructed, and the statistical mechanics of a single particle in this environment has been investigated. In the limit of a high dimensional N → ∞, the free energy of the system in the thermodynamic limit coincides with the most general version of Derrida’s generalized random energy model. The low-temperature behavior depends essentially on the spectrum of length scales involved in the construction of the landscape. The construction is argued to be valid in any finite spatial dimensions N ≥1. The text was submitted by the authors in English.     

On Calculations of Legendre Functions and Associated Legendre Functions of the First Kind of Complex Degree

Formulas for calculating Legendre functions and associated Legendre functions of the first kind of complex degree using an Ermakov—Lewis invariant are presented. These formulas are straight-forward to implement numerically and are motivated by the lack of computational routines in standard university tools like those of MatLab and Maple. Angular waves propagating in opposite directions are also obtained. The results are particularly useful in complex angular momentum theories and nearside/farside analysis of spin-dependent angular scattering from central potentials.     

On Calculations of Legendre Functions and Associated Legendre Functions of the First Kind of Complex Degree

Formulas for calculating Legendre functions and associated Legendre functions of the first kind of complex degree using an Ermakov–Lewis invariant are presented. These formulas are straight-forward to implement numerically and are motivated by the lack of computational routines in standard university tools like those of Mat Lab and Maple.Angular waves propagating in opposite directions are also obtained. The results are particularly useful in complex angular momentum theories and nearside/farside analysis of spin-dependent angular scattering from central potentials.     

Further results on the Altarelli Parisi equations in the next to leading order

We present here to next-to-leading order, (1) a ‘one-step’ Altarelli-Parisi (A-P) equation for the singlet structure function, (2) values of anomalous dimensions which are not accessible through the operator product expansion, (3) an example of the numerical solution of the A-P equation, and (4) the inhomogeneous A-P equation for the photon structure function. All these should be helpful for the QCD analysis of scaling violation.     

On the universality of thermodynamics' Legendre transform structure

It is shown that the Legendre transform structure of thermodynamics does not depend upon the functional form of the entropy. It is a just a necessary consequence of Jaynes' maximum entropy principle. Moreover, in the important special case of the canonical ensemble, the Legendre transform structure of thermodynamics is shown to be independent of the functional form of the mean energy constraint as well.     

统计力学中的勒让德变换

勒让德变换是理论物理学中一个重要的工具,多变量函数的勒让德变换有明显的对称性.系综是统计力学教学中的核心内容.利用勒让德变换的无量纲性,从微正则系综的特性函数熵的勒让德变换出发,类比的定义了配分函数的勒让德变换.同时得到各种系综的特性函数和配分函数以及它们之间的关系和相应的热力学公式.     

The Green-Kubo Formula for the Spin-Fermion System

The spin-fermion model describes a two level quantum system (spin 1/2) coupled to finitely many free Fermi gas reservoirs which are in thermal equilibrium at inverse temperatures β _j . We consider non-equilibrium initial conditions where not all β _j are the same. It is known that, at small coupling, the combined system has a unique non-equilibrium steady state (NESS) characterized by strictly sitive entropy production. In this paper we study linear response in this NESS and prove the Green-Kubo formula and the Onsager reciprocity relations for heat fluxes generated by temperature differentials. Dedicated to Jean Michel Combes on the occasion of his sixtyfifth birthday     

原子核的核密度经验公式与核子结构函数的核效应

文中给出了原子核的核密度经验公式,建立了核密度与原子核的平均结合能之间的联系,由公式可以得出A≥12的所有核的核密度值.利用公式给出的C,Al,Ca,Fe,Sn和Pb核的核密度值及核子结构函数核效应的核密度模型,计算了核效应函数R^A1/A2(x,Q²),所得结果与μ子实验合作组测得的实验结果符合甚好.     

Singularity Time Scale of the Kardar–Parisi–Zhang Equation in 2+1 Dimensions

A master equation for the Kardar–Parisi–Zhang (KPZ) equation in 2+1 dimensions is developed. In the fully nonlinear regime we determine the finite time scale of the singularity formation in terms of the characteristics of forcing. The exact probability density function of the one point height field is obtained correspondingly.     

Legendre transformation of a self-interacting polymer chain

The end-to-end distribution function for a polymer chain with self-interaction is derived from a functional having the significance of a generator for connected diagrams which consist of vertices representing clusters of monomers in contact, and lines representing free polymer sections. In spite of the dependence of the vertex weights on the multiplicities of the contacts and the presence of an extra weight-factor peculiar to the polymer chain, the generator for connected diagrams is shown to be expressible in terms of a similar generator for irreducible diagrams through a reduction procedure that is analogous to the transformation from connected to irreducible cluster diagrams in classical gas theory. The relation between the generators for connected and irreducible diagrams can be cast into the form of a functional Legendre transformation by considering them as characteristic functionals of new activity and density functions, that embody the multiplicity dependent cluster activity and densities figuring as vertex weights in the connected and irreducible diagrams respectively. This Legendre transformation can be reduced to a much simpler form by imposing an upper bound to the allowed contact multiplicity of the interacting chain.     

Random magnetic interactions and spin glass order competing with superconductivity: Interference of the quantum Parisi phase

We analyse the competition between spin glass (SG) order and local pairing superconductivity (SC) in the fermionic Ising spin glass with frustrated fermionic spin interaction and nonrandom attractive interaction. The phase diagram is presented for all temperatures T and chemical potentials μ. SC-SG transitions are derived for the relevant ratios between attractive and frustrated-magnetic interaction. Characteristic features of pairbreaking caused by random magnetic interaction and/or by spin glass proximity are found. The existence of low-energy excitations, arising from replica permutation symmetry breaking (RPSB) in the Quantum Parisi Phase, is shown to be relevant for the SC-SG phase boundary. Complete 1-step RPSB-calculations for the SG-phase are presented together with a few results for -step breaking. Suppression of reentrant SG-SC-SG transitions due to RPSB is found and discussed in context of ferromagnet-SG boundaries. The relative positioning of the SC and SG phases presents a theoretical landmark for comparison with experiments in heavy fermion systems and high superconductors. We find a crossover line traversing the SG-phase with as its quantum critical (end)point in complete RPSB, and scaling is proposed for its vicinity. We argue that this line indicates a random field instability and suggest Dotsenko-Mézard vector replica symmetry breaking to occur at low temperatures beyond. Received 26 November 1998 and Received in final form 25 January 1999     

Free Analog of Pressure and Its Legendre Transform

The free analog of the pressure is introduced for multivariate noncommutative random variables and its Legendre transform is compared with Voiculescus microstate free entropy.Supported in part by Grant-in-Aid for Scientific Research (C)14540198 and by the program R&D support scheme for funding selected IT proposals of the Ministry of Public Management, Home Affairs, Posts and Telecommunications.