478 research outputs found

    Topological expansion of the 2-matrix model correlation functions: diagrammatic rules for a residue formula

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    We solve the loop equations of the hermitian 2-matrix model to all orders in the topological 1/N21/N^2 expansion, i.e. we obtain all non-mixed correlation functions, in terms of residues on an algebraic curve. We give two representations of those residues as Feynman-like graphs, one of them involving only cubic vertices.Comment: 48 pages, LaTex, 68 figure

    Mixed Correlation Functions of the Two-Matrix Model

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    We compute the correlation functions mixing the powers of two non-commuting random matrices within the same trace. The angular part of the integration was partially known in the literature: we pursue the calculation and carry out the eigenvalue integration reducing the problem to the construction of the associated biorthogonal polynomials. The generating function of these correlations becomes then a determinant involving the recursion coefficients of the biorthogonal polynomials.Comment: 16 page

    Enumeration of maps with self avoiding loops and the O(n) model on random lattices of all topologies

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    We compute the generating functions of a O(n) model (loop gas model) on a random lattice of any topology. On the disc and the cylinder, they were already known, and here we compute all the other topologies. We find that the generating functions (and the correlation functions of the lattice) obey the topological recursion, as usual in matrix models, i.e they are given by the symplectic invariants of their spectral curve.Comment: pdflatex, 89 pages, 12 labelled figures (15 figures at all), minor correction

    2-matrix versus complex matrix model, integrals over the unitary group as triangular integrals

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    We prove that the 2-hermitean matrix model and the complex-matrix model obey the same loop equations, and as a byproduct, we find a formula for Itzykzon-Zuber's type integrals over the unitary group. Integrals over U(n) are rewritten as gaussian integrals over triangular matrices and then computed explicitly. That formula is an efficient alternative to the former Shatashvili's formula.Comment: 29 pages, Late

    Topological expansion of beta-ensemble model and quantum algebraic geometry in the sectorwise approach

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    We solve the loop equations of the β\beta-ensemble model analogously to the solution found for the Hermitian matrices β=1\beta=1. For \beta=1,thesolutionwasexpressedusingthealgebraicspectralcurveofequation, the solution was expressed using the algebraic spectral curve of equation y^2=U(x).Forarbitrary. For arbitrary \beta,thespectralcurveconvertsintoaSchro¨dingerequation, the spectral curve converts into a Schr\"odinger equation ((\hbar\partial)^2-U(x))\psi(x)=0with with \hbar\propto (\sqrt\beta-1/\sqrt\beta)/N.Thispaperissimilartothesisterpaper I,inparticular,allthemainingredientsspecificforthealgebraicsolutionoftheproblemremainthesame,butherewepresentthesecondapproachtofindingasolutionofloopequationsusingsectorwisedefinitionofresolvents.Beingtechnicallymoreinvolved,itallowsdefiningconsistentlytheBcyclestructureoftheobtainedquantumalgebraiccurve(aDmoduleoftheform. This paper is similar to the sister paper~I, in particular, all the main ingredients specific for the algebraic solution of the problem remain the same, but here we present the second approach to finding a solution of loop equations using sectorwise definition of resolvents. Being technically more involved, it allows defining consistently the B-cycle structure of the obtained quantum algebraic curve (a D-module of the form y^2-U(x),where, where [y,x]=\hbar)andtoconstructexplicitlythecorrelationfunctionsandthecorrespondingsymplecticinvariants) and to construct explicitly the correlation functions and the corresponding symplectic invariants F_h,orthetermsofthefreeenergy,in1/N2, or the terms of the free energy, in 1/N^2-expansion at arbitrary \hbar. The set of "flat" coordinates comprises the potential times tkt_k and the occupation numbers \widetilde{\epsilon}_\alpha.WedefineandinvestigatethepropertiesoftheAandBcycles,formsof1st,2ndand3rdkind,andtheRiemannbilinearidentities.Weusetheseidentitiestofindexplicitlythesingularpartof. We define and investigate the properties of the A- and B-cycles, forms of 1st, 2nd and 3rd kind, and the Riemann bilinear identities. We use these identities to find explicitly the singular part of \mathcal F_0thatdependsexclusivelyon that depends exclusively on \widetilde{\epsilon}_\alpha$.Comment: 58 pages, 7 figure

    Holomorphic anomaly and matrix models

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    The genus g free energies of matrix models can be promoted to modular invariant, non-holomorphic amplitudes which only depend on the geometry of the classical spectral curve. We show that these non-holomorphic amplitudes satisfy the holomorphic anomaly equations of Bershadsky, Cecotti, Ooguri and Vafa. We derive as well holomorphic anomaly equations for the open string sector. These results provide evidence at all genera for the Dijkgraaf--Vafa conjecture relating matrix models to type B topological strings on certain local Calabi--Yau threefolds.Comment: 23 pages, LaTex, 3 figure

    Large deviations of the maximal eigenvalue of random matrices

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    We present detailed computations of the 'at least finite' terms (three dominant orders) of the free energy in a one-cut matrix model with a hard edge a, in beta-ensembles, with any polynomial potential. beta is a positive number, so not restricted to the standard values beta = 1 (hermitian matrices), beta = 1/2 (symmetric matrices), beta = 2 (quaternionic self-dual matrices). This model allows to study the statistic of the maximum eigenvalue of random matrices. We compute the large deviation function to the left of the expected maximum. We specialize our results to the gaussian beta-ensembles and check them numerically. Our method is based on general results and procedures already developed in the literature to solve the Pastur equations (also called "loop equations"). It allows to compute the left tail of the analog of Tracy-Widom laws for any beta, including the constant term.Comment: 62 pages, 4 figures, pdflatex ; v2 bibliography corrected ; v3 typos corrected and preprint added ; v4 few more numbers adde

    Mixed correlation function and spectral curve for the 2-matrix model

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    We compute the mixed correlation function in a way which involves only the orthogonal polynomials with degrees close to nn, (in some sense like the Christoffel Darboux theorem for non-mixed correlation functions). We also derive new representations for the differential systems satisfied by the biorthogonal polynomials, and we find new formulae for the spectral curve. In particular we prove the conjecture of M. Bertola, claiming that the spectral curve is the same curve which appears in the loop equations.Comment: latex, 1 figure, 55 page

    A matrix model for the topological string II: The spectral curve and mirror geometry

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    In a previous paper, we presented a matrix model reproducing the topological string partition function on an arbitrary given toric Calabi-Yau manifold. Here, we study the spectral curve of our matrix model and thus derive, upon imposing certain minimality assumptions on the spectral curve, the large volume limit of the BKMP "remodeling the B-model" conjecture, the claim that Gromov-Witten invariants of any toric Calabi-Yau 3-fold coincide with the spectral invariants of its mirror curve.Comment: 1+37 page

    Some properties of angular integrals

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    We find new representations for Itzykson-Zuber like angular integrals for arbitrary beta, in particular for the orthogonal group O(n), the unitary group U(n) and the symplectic group Sp(2n). We rewrite the Haar measure integral, as a flat Lebesge measure integral, and we deduce some recursion formula on n. The same methods gives also the Shatashvili's type moments. Finally we prove that, in agreement with Brezin and Hikami's observation, the angular integrals are linear combinations of exponentials whose coefficients are polynomials in the reduced variables (x_i-x_j)(y_i-y_j).Comment: 43 pages, Late
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