250 research outputs found
Stringy Instantons
A canonical Lorentz invariant field theory extension of collective field
theory of d=1 matrix models is presented.
We show that the low density, discrete, sector of collective field theory
includes single eigenvalue Euclidean instantons which tunnel between different
vacua of the extended theory. These "stringy" instantons induce
non-perturbative effective operators of strength . The relationship
of the world sheet description of string theory and Liouville theory to the
effective space-time theory is explained.Comment: 12 pages, One figure not included, available as eps file on reques
S matrix of collective field theory
By applying the Lehmann-Symanzik-Zimmermann (LSZ) reduction formalism, we
study the S matrix of collective field theory in which fermi energy is larger
than the height of potential. We consider the spatially symmetric and
antisymmetric boundary conditions. The difference is that S matrices are
proportional to momenta of external particles in antisymmetric boundary
condition, while they are proportional to energies in symmetric boundary
condition. To the order of , we find simple formulas for the S matrix
of general potential. As an application, we calculate the S matrix of a case
which has been conjectured to describe a "naked singularity".Comment: 19 page, LaTe
Matrix Theories from Reduced SU(N) Yang-Mills with Adjoint Fermions
We consider a dimensional reduction of 3+1 dimensional SU(N) Yang-Mills
theory coupled to adjoint fermions to obtain a class of 1+1 dimensional matrix
field theories. We derive the quantized light-cone Hamiltonian in the
light-cone gauge A_- = 0 and large-N limit, and then solve for the masses,
wavefunctions and structure functions of the color singlet ``meson-like'' and
``baryon-like'' boundstates. Among the states we study are many massless
string-like states that can be solved for exactly.Comment: 13 pages, Revtex, one PS figur
Two-Dimensional String Theory, Topological Field Theories and the Deformed Matrix Model
In this paper the string theory is studied from the point of view of
topological field theories. Calculations are done for arbitrary genus. A change
in the prescription is proposed, which reproduces the results of the
deformed matrix model. It is proposed that the deformed matrix model is related
to a D-series Landau-Ginzburg superpotential.Comment: 20 pages, Latex CERN-TH.7155. Minor typos correcte
"Non-renormalization" without supersymmetry
The g_{YM} perturbed, non supersymmetric extension of the dual single matrix
description of 1/2 BPS states, within the Hilbert space reduction to the
oscillator subsector associated with chiral primaries is considered. This
matrix model is described in terms of a single hermitean matrix. It is found
that, apart from a trivial shift in the energy, the large N background,
spectrum and interaction of invariant states are independent of g_{YM}. This
property applies to more general D terms.Comment: latex, 14 pages; references added and correcte
Quantum and Classical Aspects of Deformed Strings.
The quantum and classical aspects of a deformed matrix model proposed
by Jevicki and Yoneya are studied. String equations are formulated in the
framework of Toda lattice hierarchy. The Whittaker functions now play the role
of generalized Airy functions in strings. This matrix model has two
distinct parameters. Identification of the string coupling constant is thereby
not unique, and leads to several different perturbative interpretations of this
model as a string theory. Two such possible interpretations are examined. In
both cases, the classical limit of the string equations, which turns out to
give a formal solution of Polchinski's scattering equations, shows that the
classical scattering amplitudes of massless tachyons are insensitive to
deformations of the parameters in the matrix model.Comment: 52 pages, Latex
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