1,936 research outputs found
Darboux Transformations for (2+1)-Dimensional Extensions of the KP Hierarchy
New extensions of the KP and modified KP hierarchies with self-consistent
sources are proposed. The latter provide new generalizations of
-dimensional integrable equations, including the DS-III equation and the
-wave problem. Furthermore, we recover a system that contains two types of
the KP equation with self-consistent sources as special cases. Darboux and
binary Darboux transformations are applied to generate solutions of the
proposed hierarchies
Self-duality of the compactified Ruijsenaars-Schneider system from quasi-Hamiltonian reduction
The Delzant theorem of symplectic topology is used to derive the completely
integrable compactified Ruijsenaars-Schneider III(b) system from a
quasi-Hamiltonian reduction of the internally fused double SU(n) x SU(n). In
particular, the reduced spectral functions depending respectively on the first
and second SU(n) factor of the double engender two toric moment maps on the
III(b) phase space CP(n-1) that play the roles of action-variables and
particle-positions. A suitable central extension of the SL(2,Z) mapping class
group of the torus with one boundary component is shown to act on the
quasi-Hamiltonian double by automorphisms and, upon reduction, the standard
generator S of the mapping class group is proved to descend to the Ruijsenaars
self-duality symplectomorphism that exchanges the toric moment maps. We give
also two new presentations of this duality map: one as the composition of two
Delzant symplectomorphisms and the other as the composition of three Dehn twist
symplectomorphisms realized by Goldman twist flows. Through the well-known
relation between quasi-Hamiltonian manifolds and moduli spaces, our results
rigorously establish the validity of the interpretation [going back to Gorsky
and Nekrasov] of the III(b) system in terms of flat SU(n) connections on the
one-holed torus.Comment: Final version to appear in Nuclear Physics B, with simplified proof
of Theorem 1, 56 page
AdS_5 Solutions of Type IIB Supergravity and Generalized Complex Geometry
We use the formalism of generalized geometry to study the generic
supersymmetric AdS_5 solutions of type IIB supergravity that are dual to N=1
superconformal field theories (SCFTs) in d=4. Such solutions have an associated
six-dimensional generalized complex cone geometry that is an extension of
Calabi-Yau cone geometry. We identify generalized vector fields dual to the
dilatation and R-symmetry of the dual SCFT and show that they are generalized
holomorphic on the cone. We carry out a generalized reduction of the cone to a
transverse four-dimensional space and show that this is also a generalized
complex geometry, which is an extension of Kahler-Einstein geometry.
Remarkably, provided the five-form flux is non-vanishing, the cone is
symplectic. The symplectic structure can be used to obtain Duistermaat-Heckman
type integrals for the central charge of the dual SCFT and the conformal
dimensions of operators dual to BPS wrapped D3-branes. We illustrate these
results using the Pilch-Warner solution.Comment: 56 pages; v2: minor changes, version to be published in Commun. Math.
Phy
New compact forms of the trigonometric Ruijsenaars-Schneider system
The reduction of the quasi-Hamiltonian double of that has
been shown to underlie Ruijsenaars' compactified trigonometric -body system
is studied in its natural generality. The constraints contain a parameter ,
restricted in previous works to because Ruijsenaars' original
compactification relies on an equivalent condition. It is found that allowing
generic results in the appearance of new self-dual compact forms,
of two qualitatively different types depending on the value of . The type
(i) cases are similar to the standard case in that the reduced phase space
comes equipped with globally smooth action and position variables, and turns
out to be symplectomorphic to as a Hamiltonian toric
manifold. In the type (ii) cases both the position variables and the action
variables develop singularities on a nowhere dense subset. A full
classification is derived for the parameter according to the type (i)
versus type (ii) dichotomy. The simplest new type (i) systems, for which , are described in some detail as an illustration.Comment: 31 page
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