13 research outputs found
A 2D Inspired 4D Theory of Gravity
Coadjoint orbits of the Virasoro and Kac-Moody algebras provide geometric
actions for matter coupled to gravity and gauge fields in two dimensions.
However, the Gauss' law constraints that arise from these actions are not
necessarily endemic to two-dimensional topologies. Indeed the constraints
associated with Yang-Mills naturally arise from the coadjoint orbit
construction of the WZW model. One may in fact use a Yang-Mills theory to
provide dynamics to the otherwise fixed coadjoint vectors that define the
orbits. In this letter we would like to exhibit an analogue of the Yang-Mills
classical action for the diffeomorphism sector. With this analogue one may
postulate a 4D theory of gravitation that is related to an underlying two
dimensional theory. Instead of quadratic differentials, a (1,3) pseudo tensor
becomes the dynamical variable. We briefly discuss how this tensor may be
classically coupled to matter.Comment: 8 pages, UI-94-11 (minor typos corrected in eq 11 and eq 2
Supergravity solutions with AdS(4) from non-Abelian T-dualities
We present a large class of new backgrounds that are solutions of type II supergravity with a warped AdS(4) factor, non-trivial axion-dilaton, B-field, and three-and five-form Ramond-Ramond fluxes. We obtain these solutions by applying non-Abelian T-dualities with respect to SU(2) or SU(2)/U(1) isometries to reductions to 10d IIA of 11d sugra solutions of the form AdS(4) x Y-7, with Y-7 = S-7/Z(k), S-7, M-1,M-1,M-1, Q(1,1,1) and N(1,1). The main class of reductions to IIA is along the Hopf fiber and leads to solutions of the form AdS(4) x K-6, where K-6 is Kahler Einstein with K-6 = CP3, S-2 x CP2, S-2 x S-2 x S-2; the first member of this class is dual to the ABJM field theory in the 't Hooft limit. We also consider other less symmetric but susy preserving reductions along circles that are not the Hopf fiber. In the case of N(1,1) we find an additional breaking of isometries in the NAT-dual background. To initiate the study of some properties of the field theory dual, we explicitly compute the central charge holographically.SP1
Yang-Mills, Gravity, and String Symmetries
In this work we use constructs from the dual space of the semi-direct product
of the Virasoro algebra and the affine Lie algebra of a circle to write a
theory of gravitation which is a natural analogue of Yang-Mills theory. The
theory provides a relation between quadratic differentials in 1+1 dimensions
and rank two symmetric tensors in higher dimensions as well as a covariant
local Lagrangian for two dimensional gravity. The isotropy equations of
coadjoint orbits are interpreted as Gauss law constraints for a field theory in
two dimensions, which enables us to extend to higher dimensions. The theory has
a Newtonian limit in any space-time dimension. Our approach introduces a novel
relationship between string theories and 2D field theories that might be useful
in defining dual theories. We briefly discuss how this gravitational field
couples to fermions.Comment: To Appear in Phys. Lett. B, In memory of Emma Meuric
Irreducible Decomposition of Products of 10D Chiral Sigma Matrices
We review the enveloping algebra of the 10 dimensional chiral sigma matrices.
To facilitate the computation of the product of several chiral sigma matrices
we have developed a symbolic program. Using this program one can reduce the
multiplication of the sigma matrices down to linear combinations of irreducilbe
elements. We are able to quickly derive several identities that are not
restricted to traces. A copy of the program written in the Mathematica language
is provided for the community.Comment: 28 pages, Mathematica Program sigmavector10D.nb is included.
Submitted ot CP
The Image of Self Intersecting QCD Strings in Four Dimensions
We numerically examine the self-dual solutions of self-intersecting strings
immersed in four dimensions. We find that open torus knots have topologies that
can support monopole/anti-monopole as well as q-qbar production and
annihilation. We give an estimate of the string tension from quark production
rates, show that the intersection number for torus-knots is 4(p-q), and discuss
a chiral symmetry breaking mechanism due to self-intersections. We supply a
MAPLE program that can annimate the torus-knot solutions. These annimations can
be found at http://www-hep.physics.uiowa.edu/~bacus/research.html under the
``Animation Control Panel''.Comment: 15 pages Latex, 39 figures, corrected typos and spellin
A Truly Crazy Idea About Type-IIB Supergravity and Heterotic Sigma-Models
We construct an explicit and manifestly (1,0) heterotic sigma-model where the
background fields are those of 10D, N=IIB supergravity.Comment: 10 Pages, Latex (self contained macros
A Study of Fermions Coupled to Gauge and Gravitational Fields on a Cylinder
Fermions on a cylinder coupled to gravity and gauge fields are examined by
studying the geometric action associated with the symmetries of such a system.
The gauge coupling constant is shown to be constrained and the effect of
gravity on the masses is discussed. Furthermore, we introduce a new
gravitational theory which couples to the fermions by promoting the coadjoint
vector of the diffeomorphism sector to a dynamical variable. This system,
together with the gauge sector is shown to be equivalent to a one dimensional
system.Comment: 16 pages, UI-94-2 (Some minor typographical errors are cleaned up.
Chiral Supergravitons Interacting with a 0-Brane N-Extended NSR Super-Virasoro Group
We continue the development of the actions, S_{AFF}, by examining the cases
where there are N fermionic degrees of freedom associated with a 0-brane. These
actions correspond to the interaction of the N-extended super Virasoro algebra
with the supergraviton and the associated SO(N) gauge field that accompanies
the supermultiplet. The superfield formalism is used throughout so that
supersymmetry is explicit.Comment: PACS: 04.65.+e, 11.15.-q, 11.25.-w, 12.60.
Classical Open String Models in 4-Dim Minkowski Spacetime
Classical bosonic open string models in fourdimensional Minkowski spacetime
are discussed. A special attention is paid to the choice of edge conditions,
which can follow consistently from the action principle. We consider
lagrangians that can depend on second order derivatives of worldsheet
coordinates. A revised interpretation of the variational problem for such
theories is given. We derive a general form of a boundary term that can be
added to the open string action to control edge conditions and modify
conservation laws. An extended boundary problem for minimal surfaces is
examined. Following the treatment of this model in the geometric approach, we
obtain that classical open string states correspond to solutions of a complex
Liouville equation. In contrast to the Nambu-Goto case, the Liouville potential
is finite and constant at worldsheet boundaries. The phase part of the
potential defines topological sectors of solutions.Comment: 25 pages, LaTeX, preprint TPJU-28-93 (the previous version was
truncated by ftp...