STABILIZED MATRIX MODELS FOR NONPERTURBATIVE TWO-DIMENSIONAL QUANTUM GRAVITY

1994 ◽  
Vol 09 (21) ◽  
pp. 3751-3771 ◽  
Author(s):  
JOSHUA FEINBERG

A thorough analysis of stochastically stabilized Hermitian one-matrix models for two-dimensional quantum gravity at all its (2, 2k − 1) multicritical points is made. It is stressed that only the zero fermion sector of the supersymmetric Hamiltonian, i.e. the forward Fokker–Planck Hamiltonian, is relevant for the analysis of bosonic matter coupled to two-dimensional gravity. Therefore, supersymmetry breaking is not the physical mechanism that creates nonperturbative effects in the case of points of even multicriticality k. Nonperturbative effects in the string coupling constant g str result in a loss of any explicit relation to the KdV hierarchy equations in the latter case, while maintaining the perturbative genus expansion. As a by-product of our analysis it is explicitly proved that polynomials orthogonal relative to an arbitrary weight exp (−βV (x)) along the whole real line obey a Hartree–Fock equation.

1991 ◽  
Vol 06 (15) ◽  
pp. 2743-2754 ◽  
Author(s):  
NORISUKE SAKAI ◽  
YOSHIAKI TANII

The radius dependence of partition functions is explicitly evaluated in the continuum field theory of a compactified boson, interacting with two-dimensional quantum gravity (noncritical string) on Riemann surfaces for the first few genera. The partition function for the torus is found to be a sum of terms proportional to R and 1/R. This is in agreement with the result of a discretized version (matrix models), but is quite different from the critical string. The supersymmetric case is also explicitly evaluated.


1991 ◽  
Vol 06 (08) ◽  
pp. 1385-1406 ◽  
Author(s):  
MASAFUMI FUKUMA ◽  
HIKARU KAWAI ◽  
RYUICHI NAKAYAMA

We study the continuum Schwinger-Dyson equations for nonperturbative two-dimensional quantum gravity coupled to various matter fields. The continuum Schwinger-Dyson equations for the one-matrix model are explicitly derived and turn out to be a formal Virasoro condition on the square root of the partition function, which is conjectured to be the τ function of the KdV hierarchy. Furthermore, we argue that general multi-matrix models are related to the W algebras and suitable reductions of KP hierarchy and its generalizations.


2017 ◽  
Vol 32 (31) ◽  
pp. 1750180
Author(s):  
Badis Ydri ◽  
Cherine Soudani ◽  
Ahlam Rouag

We present a new model of quantum gravity as a theory of random geometries given explicitly in terms of a multitrace matrix model. This is a generalization of the usual discretized random surfaces of two-dimensional quantum gravity which works away from two dimensions and captures a large class of spaces admitting a finite spectral triple. These multitrace matrix models sustain emergent geometry as well as growing dimensions and topology change.


1995 ◽  
Vol 10 (34) ◽  
pp. 2589-2597 ◽  
Author(s):  
OSCAR DIEGO

In this letter we study the universality of the nonperturbative effects and the vacua structure of the stochastic stabilization of the matrix models which defines pure 2-D quantum gravity.


1992 ◽  
Vol 07 (11) ◽  
pp. 2601-2634 ◽  
Author(s):  
GREGORY MOORE ◽  
NATHAN SEIBERG

We discuss a target space field theory of macroscopic loops W(ℓ,…) in two-dimensional gravity. The propagator <W(ℓ1)W(ℓ2)> and topology-changing amplitudes <W(ℓ1)W(ℓ2)W(ℓ3)> (string interactions) are considered as off-shell Euclidean Green's functions in this field theory. In the course of the analysis, we identify a new set of operators in the c = 1 system and interpret them in two-dimensional gravity. We also identify an infinite set of new conserved charges in the c = 1 system which are associated with the special states in the theory. The analysis also shows that the eigenvalue coordinate of the matrix model and a zero mode of the Liouville field are not functionally related but are conjugate variables in an integral transform.


1991 ◽  
Vol 69 (7) ◽  
pp. 837-854 ◽  
Author(s):  
David Sénéchal

A review of the main results recently obtained in the study of two-dimensional quantum gravity is offered. The analysis of two-dimensional quantum gravity by the methods of conformal field theory is briefly described. Then the treatment of quantum gravity in terms of matrix models is explained, including the notions of continuum limit, planar approximation, and orthogonal polynomials. Correlation fonctions are also treated, as well as phases of the matrix models.


1992 ◽  
Vol 07 (18) ◽  
pp. 1651-1660 ◽  
Author(s):  
SIMON DALLEY

The Weingarten lattice gauge model of Nambu-Goto strings is generalized to allow for fluctuations of an intrinsic worldsheet metric through a dynamical quadrilation. The continuum limit is taken for c≤1 matter, reproducing the results of Hermitian matrix models to all orders in the genus expansion. For the compact c=1 case the vortices are Wilson lines, whose exclusion leads to the theory of non-interacting fermions. As a by-product of the analysis one finds the critical behavior of SOS and vertex models coupled to 2D quantum gravity.


1991 ◽  
Vol 06 (31) ◽  
pp. 2901-2908 ◽  
Author(s):  
JONATHAN D. EDWARDS ◽  
IGOR R. KLEBANOV

Using a matrix model, we calculate sums over surfaces with macroscopic boundaries of fixed lengths in two-dimensional gravity coupled to a pair of anti-commuting scalar fields with c=-2. For n boundaries, the answer depends only on the sum of their lengths and is given explicitly in terms of Bessel functions to all orders of the genus expansion. For n=1, this defines the Hartle-Hawking ground state wave function of the universe, which is shown to satisfy the minisuperspace Wheeler–De Witt equation with a boundary condition imposed at small geometries.


1993 ◽  
Vol 08 (07) ◽  
pp. 1185-1244 ◽  
Author(s):  
KREŠIMIR DEMETERFI

We review some results of the recent progress in understanding two-dimensional quantum gravity and low-dimensional string theories based on the lattice approach. The possibility to solve the lattice models exactly comes from their equivalence to large N matrix models. We describe various matrix models and their continuum limits, and discuss in some detail the phase structure of Hermitian one-matrix models. For the one-dimensional matrix model we discuss its field theoretic formulation through a collective field method and summarize some perturbative results. We compare the results obtained from matrix models to the results in the continuum approach to string theory.


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