Solitons and giants in matrix models

We present a method for solving BPS equations obtained in the collective-field approach to matrix models. The method enables us to find BPS solutions and quantum excitations around these solutions in the one-matrix model, and in general for the Calogero model. These semiclassical solutions correspond to giant gravitons described by matrix models obtained in the framework of AdS/CFT correspondence. The two-field model, associated with two types of giant gravitons, is investigated. In this duality-based matrix model we find the finite form of the $n$-soliton solution. The singular limit of this solution is examined and a realization of open-closed string duality is proposed.Comment: 17 pages, JHEP cls; v2: final version to appear in JHEP, 2 references added, physical motivation and interpretation clarifie

Multi-vortex solution in the Sutherland model

We consider the large-$N$ Sutherland model in the Hamiltonian collective-field approach based on the $1/N$ expansion. The Bogomol'nyi limit appears and the corresponding solutions are given by static-soliton configurations. They exist only for \l<1, i.e. for the negative coupling constant of the Sutherland interaction. We determine their creation energies and show that they are unaffected by higher-order corrections. For \l=1, the Sutherland model reduces to the free one-plaquette Kogut-Susskind model.Comment: Latex, using ioplppt.sty, 11 page

Solitons and excitations in the duality-based matrix model

We analyse a specific, duality-based generalization of the hermitean matrix model. The existence of two collective fields enables us to describe specific excitations of the hermitean matrix model. By using these two fields, we construct topologically non-trivial solutions (BPS solitons) of the model. We find the low-energy spectrum of quantum fluctuations around the uniform solution. Furthermore, we construct the wave functional of the ground state and obtain the corresponding Green function.Comment: 13 pages,v2: new solutions constructed, title changed accordingl

Waves and Solitons in the Continuum Limit of the Calogero-Sutherland Model

We examine a collection of particles interacting with inverse-square two-body potentials in the thermodynamic limit. We find explicit large-amplitude density waves and soliton solutions for the motion of the system. Waves can be constructed as coherent states of either solitons or phonons. Therefore, either solitons or phonons can be considered as the fundamental excitations. The generic wave is shown to correspond to a two-band state in the quantum description of the system, while the limiting cases of solitons and phonons correspond to particle and hole excitations.Comment: Version to appear in Physical Rerview Letters; contains some new results and explanation

Density Correlation Functions in Calogero Sutherland Models

Using arguments from two dimensional Yang-Mills theory and the collective coordinate formulation of the Calogero-Sutherland model, we conjecture the dynamical density correlation function for coupling $l$ and $1/l$, where $l$ is an integer. We present overwhelming evidence that the conjecture is indeed correct.Comment: 12 pages phyzzx, CERN-TH/94.7243 One reference change

Comment on ``Low-dimensional Bose liquids: beyond the Gross-Pitaevskii approximation''

This is a comment on the work of Kolomeisky et al., Phys. Rev. Lett. 85, 1146 (2000). We point out that they are using the wrong form of the energy functional for one-dimensional fermions. We point out two possible forms of the energy functional, both of which can be derived from first principles but using different methods. One is obtained from the collective field theory method, while the other is derived from the extended Thomas-Fermi method. These two forms of the energy functional do not support the soliton solutions which are obtained by Kolomeisky et al.Comment: Revtex, 2 page

SELF-DUAL ANYONS IN UNIFORM BACKGROUND FIELDS

We study relativistic self-dual Chern-Simons-Higgs systems in the presence of uniform background fields that explicitly break CTP. A rich, but discrete vacuum structure is found when the gauge symmetry is spontaneously broken, while the symmetric phase can have an infinite vacuum degeneracy at tree level. The latter is due to the proliferation of neutral solitonic states that cost zero energy. Various novel self-dual solitons, such as these, are found in both the symmetric and the asymmetric phases. Also by considering a similar system on a two-sphere and the subsequent large sphere limit, we isolate sensible and finite expressions for the conserved angular and linear momenta, which satisfy anomalous commutation relations. We conclude with a few remarks on unresolved issues.Comment: LaTeX, 20 pages, 4 uuencoded figures included

On The Problem of Particle Production in c=1 Matrix Model

We reconsider and analyze in detail the problem of particle production in the time dependent background of $c=1$ matrix model where the Fermi sea drains away at late time. In addition to the moving mirror method, which has already been discussed in hep-th/0403169 and hep-th/0403275, we describe yet another method of computing the Bogolubov coefficients which gives the same result. We emphasize that these Bogolubov coefficients are approximately correct for small value of the deformation parameter. We also study the time evolution of the collective field theory stress-tensor with a special point-splitting regularization. Our computations go beyond the approximation of the previous treatments and are valid at large coordinate distances from the boundary at a finite time and up-to a finite coordinate distance from the boundary at late time. In this region of validity our regularization produces a certain singular term that is precisely canceled by the collective field theory counter term in the present background. The energy and momentum densities fall off exponentially at large distance from the boundary to the values corresponding to the static background. This clearly shows that the radiated energy reaches the asymptotic region signaling the space-time decay.Comment: 37 pages, 5 figures. Section 6 is modified to clarify main accomplishments of the paper including a discussion comparing stress-tensor analysis with those preexisted in literature. Other modifications include minor changes in the text and addition of one reference. Version accepted for publication in JHE

Particle Production in Matrix Cosmology

We consider cosmological particle production in 1+1 dimensional string theory. The process is described most efficiently in terms of anomalies, but we also discuss the explicit mode expansions. In matrix cosmology the usual vacuum ambiguity of quantum fields in time-dependent backgrounds is resolved by the underlying matrix model. This leads to a finite energy density for the "in" state which cancels the effect of anomalous particle production.Comment: 24 pages, 1 figure; v2: references added, minor change