4,990 research outputs found
The Poincare' coset models ISO(d-1,1)/R^n and T-duality
We generalize a family of Lagrangians with values in the Poincar\'e group
ISO(d-1,1), which contain the description of spinning strings in flat (d-1)+1
dimensions, by including symmetric terms in the world-sheet coordinates. Then,
by promoting a subgroup H=R^n, n less than or equal to d, which acts
invariantly from the left on the element of ISO(d-1,1), to a gauge symmetry of
the action, we obtain a family of sigma-models. They describe bosonic strings
moving in (generally) curved, and in some cases degenerate, space-times with an
axion field. Further, the space-times of the effective theory admit in general
T-dual geometries. We give explicit results for two non degenerate cases.Comment: LaTeX, 24 pages, no figure
Geometry of Batalin-Vilkovisky quantization
The present paper is devoted to the study of geometry of Batalin-Vilkovisky
quantization procedure. The main mathematical objects under consideration are
P-manifolds and SP-manifolds (supermanifolds provided with an odd symplectic
structure and, in the case of SP-manifolds, with a volume element). The
Batalin-Vilkovisky procedure leads to consideration of integrals of the
superharmonic functions over Lagrangian submanifolds. The choice of Lagrangian
submanifold can be interpreted as a choice of gauge condition; Batalin and
Vilkovisky proved that in some sense their procedure is gauge independent. We
prove much more general theorem of the same kind. This theorem leads to a
conjecture that one can modify the quantization procedure in such a way as to
avoid the use of the notion of Lagrangian submanifold. In the next paper we
will show that this is really so at least in the semiclassical approximation.
Namely the physical quantities can be expressed as integrals over some set of
critical points of solution S to the master equation with the integrand
expressed in terms of Reidemeister torsion. This leads to a simplification of
quantization procedure and to the possibility to get rigorous results also in
the infinite-dimensional case. The present paper contains also a compete
classification of P-manifolds and SP-manifolds. The classification is
interesting by itself, but in this paper it plays also a role of an important
tool in the proof of other results.Comment: 13 page
Free Fields Equations For Space-Time Algebras With Tensorial Momentum
Free field equations, with various spins, for space-time algebras with
second-rank tensor (instead of usual vector) momentum are constructed. Similar
algebras are appearing in superstring/M theories. The most attention is payed
to the gauge invariance properties, particularly the spin two equations with
gauge invariance are constructed for dimensions 2+2 and 2+4 and connection to
Einstein equation and diffeomorphism invariance is established
Towards SO(2,10)-Invariant M-Theory: Multilagrangian Fields
The SO(2,10) covariant extension of M-theory superalgebra is considered, with
the aim to construct a correspondingly generalized M-theory, or 11d
supergravity. For the orbit, corresponding to the supergravity multiplet,
the simplest unitary representations of the bosonic part of this algebra, with
sixth-rank tensor excluded, are constructed on a language of field theory in
66d space-time. The main peculiarities are the presence of more than one
equation of motion and corresponding Lagrangians for a given field and that the
gauge and SUSY invariances of the theory mean that the sum of variations of
these Lagrangians (with different variations of the same field) is equal to
zero.Comment: Latex 16 pages, minor correction, To appear in Mod. Phys. Lett.
Holographic repulsion and confinement in gauge theory
We show that for asymptotically anti-deSitter backgrounds with negative
energy, such as the AdS soliton and regulated negative mass AdS-Schwarzshild
metrics, the Wilson loop expectation value in the AdS/CFT conjecture exhibits a
Coulomb to confinement transition. We also show that the quark-antiquark () potential can be interpreted as affine time along null geodesics on
the minimal string world sheet,and that its intrinsic curvature provides a
signature of transition to confinement phase. The result demonstrates a UV/IR
relation in that the boundary separation of the pair exhibits an
inverse relationship with the radial descent of the world sheet into the bulk.
Our results suggest a generic (holographic) relationship between confinement in
gauge theory and repulsive gravity, which in turn is connected with singularity
avoidance in quantum gravity.Comment: 8 pages, 4 figure
BRST Formulation of 4-Monopoles
A supersymmetric gauge invariant action is constructed over any 4-dimensional
Riemannian manifold describing Witten's theory of 4-monopoles. The topological
supersymmetric algebra closes off-shell. The multiplets include the auxiliary
fields and the Wess-Zumino fields in an unusual way, arising naturally from
BRST gauge fixing. A new canonical approach over Riemann manifolds is followed,
using a Morse function as an euclidean time and taking into account the BRST
boundary conditions that come from the BFV formulation. This allows a
construction of the effective action starting from gauge principles.Comment: 18 pages, Amste
Residues and World-Sheet Instantons
We reconsider the question of which Calabi-Yau compactifications of the
heterotic string are stable under world-sheet instanton corrections to the
effective space-time superpotential. For instance, compactifications described
by (0,2) linear sigma models are believed to be stable, suggesting a remarkable
cancellation among the instanton effects in these theories. Here, we show that
this cancellation follows directly from a residue theorem, whose proof relies
only upon the right-moving world-sheet supersymmetries and suitable compactness
properties of the (0,2) linear sigma model. Our residue theorem also extends to
a new class of "half-linear" sigma models. Using these half-linear models, we
show that heterotic compactifications on the quintic hypersurface in CP^4 for
which the gauge bundle pulls back from a bundle on CP^4 are stable. Finally, we
apply similar ideas to compute the superpotential contributions from families
of membrane instantons in M-theory compactifications on manifolds of G_2
holonomy.Comment: 47 page
Ising model with a boundary magnetic field - an example of a boundary flow
In hep-th/0312197 a nonperturbative proof of the g-theorem of Affleck and
Ludwig was put forward. In this paper we illustrate how the proof of
hep-th/0312197 works on the example of the 2D Ising model at criticality
perturbed by a boundary magnetic field. For this model we present explicit
computations of all the quantities entering the proof including various contact
terms. A free massless boson with a boundary mass term is considered as a
warm-up example.Comment: 1+20 pages, Latex, 2 eps figures; v2: references adde
Superstrings and Topological Strings at Large N
We embed the large N Chern-Simons/topological string duality in ordinary
superstrings. This corresponds to a large duality between generalized gauge
systems with N=1 supersymmetry in 4 dimensions and superstrings propagating on
non-compact Calabi-Yau manifolds with certain fluxes turned on. We also show
that in a particular limit of the N=1 gauge theory system, certain
superpotential terms in the N=1 system (including deformations if spacetime is
non-commutative) are captured to all orders in 1/N by the amplitudes of
non-critical bosonic strings propagating on a circle with self-dual radius. We
also consider D-brane/anti-D-brane system wrapped over vanishing cycles of
compact Calabi-Yau manifolds and argue that at large they induce a shift in
the background to a topologically distinct Calabi-Yau, which we identify as the
ground state system of the Brane/anti-Brane system.Comment: 30 pages, some minor clarifications adde
A Center-Symmetric 1/N Expansion
The free energy of U(N) gauge theory is expanded about a center-symmetric
topological background configuration with vanishing action and vanishing
Polyakov loops. We construct this background for SU(N) lattice gauge theory and
show that it uniquely describes center-symmetric minimal action orbits in the
limit of infinite lattice volume. The leading contribution to the free energy
in the 1/N expansion about this background is of O(N^0) rather than O(N^2) as
one finds when the center symmetry is spontaneously broken. The contribution of
planar 't Hooft diagrams to the free energy is O(1/N^2) and sub-leading in this
case. The change in behavior of the diagrammatic expansion is traced to Linde's
observation that the usual perturbation series of non-Abelian gauge theories
suffers from severe infrared divergences. This infrared problem does not arise
in a center-symmetric expansion. The 't Hooft coupling \lambda=g^2 N is found
to decrease proportional to 1/\ln(N) for large N. There is evidence of a
vector-ghost in the planar truncation of the model.Comment: 27 pages, 2 figures; extended and corrected version with additional
material and reference
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