9,274 research outputs found
Toda lattice field theories, discrete W algebras, Toda lattice hierarchies and quantum groups
In analogy with the Liouville case we study the Toda theory on the
lattice and define the relevant quadratic algebra and out of it we recover the
discrete algebra. We define an integrable system with respect to the
latter and establish the relation with the Toda lattice hierarchy. We compute
the the relevant continuum limits. Finally we find the quantum version of the
quadratic algebra.Comment: 12 pages, LaTe
Normal Bundles, Pfaffians and Anomalies
We deal with the problem of diffeomorphism anomaly in theories with branes.
In particular we thoroughly analyze the problem of the residual chiral anomaly
of a five-brane immersed in M-theory, paying attention to its global
formulation in the five-brane world-volume. We conclude that the anomaly can be
canceled by a {\it local} counterterm in the five-brane world-volume.Comment: 17 pages, Latex, sign convention changed, typos correcte
String k-anomalies and D=10 Supergravity constraints: the solution of a puzzle
The --anomaly cancellation mechanism in the heterotic superstring
determines the superspace constraints for N=1, D=10
Supergravity--Super--Yang--Mills theory. We point out that the constraints
found recently in this way appear to disagree with superspace solutions found
in the past. We solve this puzzle establishing perfect agreement between the
two methods.Comment: 9 pages, Plain TeX, no figures, Abstract printed as last pag
Chiral anomalies in noncommutative gauge theories
Using cohomological methods we discuss several issues related to chiral
anomalies in noncommutative U(N) YM theories in any even dimension. We show
that for each dimension there is only one solution of the WZ consistency
condition and that there cannot be any reducible anomaly, nor any mixed anomaly
when the gauge group is a product group. We also clarify some puzzling aspects
of the issue of the anomaly when chiral fermions are in the adjoint
representation.Comment: 12 pages, Latex, typos and semantic ambiguities correcte
Two-matrix model and c=1 string theory
We show that the most general two--matrix model with bilinear coupling
underlies string theory. More precisely we prove that
constraints, a subset of the correlation functions and the integrable hierarchy
characterizing such two--matrix model, correspond exactly to the
constraints, to the discrete tachyon correlation functions and to the
integrable hierarchy of the string.Comment: 12 pages, LaTeX, SISSA 54/94/EP (misprints corrected
Duality in Supergravity Theories
We present a unified treatment in superspace of the two dual formulations of
, {\it pure} supergravity based on a strictly super-geometrical
framework: the only fundamental objects are the super Riemann curvature and
torsion, and the related Bianchi identities are sufficient to set the theory on
shell; there is no need to introduce, from the beginning, closed three- or
seven-superforms. This formulation extends also to {\it non minimal} models.
Moreover, in this framework the algebraic analogy between pure super
Yang--Mills theories and pure supergravity in is manifest. As an
additional outcome in the present formulation the supersymmetric partner of the
ABBJ-Lorentz anomaly in pure supergravity can be computed in complete
analogy to the ABBJ-gauge anomaly in supersymmetric Yang--Mills theories in ten
dimensions.
In the same framework we attack the issue of duality in ,
supergravity showing in detail that duality holds at the kinematical level in
superspace while it is broken by the dynamics. We discuss also possible
extensions of this theory which could be related to quantum corrections of the
eleven dimensional membrane.Comment: 30 pages of tex, DFPD/93/TH/51 - (to appear in Nucl. Phys. B
On Discrete Symmetries of the Multi-Boson KP Hierarchies
We show that the multi-boson KP hierarchies possess a class of discrete
symmetries linking them to the discrete Toda systems. These discrete symmetries
are generated by the similarity transformation of the corresponding Lax
operator. This establishes a canonical nature of the discrete transformations.
The spectral equation, which defines both the lattice system and the
corresponding Lax operator, plays a key role in determining pertinent symmetry
structure. We also introduce a concept of the square-root lattice leading to a
family of new pseudo-differential operators with covariance under additional
B\"{a}cklund transformations.Comment: 11 pgs, LaTeX, IFT-P/75/93, UICHEP-TH/93-1
Hamiltonian structure and coset construction of the supersymmetric extensions of N=2 KdV hierarchy
A manifestly N=2 supersymmetric coset formalism is applied to analyse the
"fermionic" extensions of N=2 and KdV hierarchies. Both these
hierarchies can be obtained from a manifest N=2 coset construction. This coset
is defined as the quotient of some local but non-linear superalgebra by a
subalgebra. Three superextensions of N=2 KdV hierarchy are
proposed, among which one seems to be entirely new.Comment: 11 pages, Latex, a few modifications in the tex
Hamiltonian Structures of the Multi-Boson KP Hierarchies, Abelianization and Lattice Formulation
We present a new form of the multi-boson reduction of KP hierarchy with Lax
operator written in terms of boson fields abelianizing the second Hamiltonian
structure. This extends the classical Miura transformation and the
Kupershmidt-Wilson theorem from the (m)KdV to the KP case. A remarkable
relationship is uncovered between the higher Hamiltonian structures and the
corresponding Miura transformations of KP hierarchy, on one hand, and the
discrete integrable models living on {\em refinements} of the original lattice
connected with the underlying multi-matrix models, on the other hand. For the
second KP Hamiltonian structure, worked out in details, this amounts to finding
a series of representations of the nonlinear \hWinf algebra in terms of
arbitrary finite number of canonical pairs of free fields.Comment: 12 pgs, (changes in abstract, intro and outlook+1 ref added). LaTeX,
BGU-94 / 1 / January- PH, UICHEP-TH/94-
Exact Results on Equations of Motion in Vacuum String Field Theory
We prove some algebraic relations on the translationally invariant solutions
and the lump solutions in vacuum string field theory. We show that up to the
subtlety at the midpoint the definition of the half-string projectors of the
known sliver solution can be generalized to other solutions. We also find that
we can embed the translationally invariant solution into the matrix equation of
motion with the zero mode.Comment: 12 pages, no figures, LaTeX2e, v2: references adde
- …