903 research outputs found
T-Duality and Two-Loop Renormalization Flows
Manifest T-duality covariance of the one-loop renormalization group flows is
shown for a generic bosonic sigma model with an abelian isometry, by referring
a set of previously derived consistency conditions to the tangent space of the
target. For a restricted background, T-duality transformations are then studied
at the next order, and the ensuing consistency conditions are found to be
satisfied by the two-loop Weyl anomaly coefficients of the model. This
represents an extremely non-trivial test of the covariance of renormalization
group flows under T-duality, and a stronger condition than T-duality invariance
of the string background effective action.Comment: 18 pp., plain TeX + harvmac. Typos in Eqs. (4.3), (4.5) and (4.7)
corrected, and references adde
Correlation function of circular Wilson loop with two local operators and conformal invariance
We consider the correlation function of a circular Wilson loop with two local
scalar operators at generic 4-positions in planar N=4 supersymmetric gauge
theory. We show that such correlator is fixed by conformal invariance up to a
function of 't Hooft coupling and two scalar combinations of the positions
invariant under the conformal transformations preserving the circle. We compute
this function at leading orders at weak and strong coupling for some simple
choices of local BPS operators. We also check that correlators of an infinite
line Wilson loop with local operators are the same as those for the circular
loop.Comment: 26 pages. v2: reference added, misprints correcte
Duality Transformations Away From Conformal Points
Target space duality transformations are considered for bosonic sigma models
and strings away from RG fixed points. A set of consistency conditions are
derived, and are seen to be nontrivially satisfied at one-loop order for
arbitrary running metric, antisymmetric tensor and dilaton backgrounds. Such
conditions are sufficiently stringent to enable an independent determination of
the sigma model beta functions at this order.Comment: 11 pages, plain TeX. Uses harvmac.te
Non-Abelian Born-Infeld theory without the square root
A non-Abelian Born-Infeld theory is presented. The square root structure that
characterizes the Dirac-Born-Infeld (DBI) action does not appear. The procedure
is based on an Abelian theory proposed by Erwin Schr\"{o}dinger that, as he
showed, is equivalent to Born-Infeld theory. We briefly mention other possible
similar proposals. Our results could be of interest in connection with string
theory and possible extensions of well known physical results in the usual
Born-Infeld Abelian case.Comment: 9 pages, no figures, revtex
Generating Functional for Gauge Invariant Actions: Examples of Nonrelativistic Gauge Theories
We propose a generating functional for nonrelativistic gauge invariant
actions. In particular, we consider actions without the usual magnetic term.
Like in the Born-Infeld theory, there is an upper bound to the electric field
strength in these gauge theories.Comment: 14 pages, 2 figures; v2: misprints correcte
Remarks on Non-Abelian Duality
A class of two-dimensional globally scale-invariant, but not conformally
invariant, theories is obtained. These systems are identified in the process of
discussing global and local scaling properties of models related by duality
transformations, based on non-semisimple isometry groups. The construction of
the dual partner of a given model is followed through; non-local as well as
local versions of the former are discussed.Comment: 33 pages, CERN-TH.7414/94, RI-9-94, WIS-7-9
On 3d N=8 Lorentzian BLG theory as a scaling limit of 3d superconformal N=6 ABJM theory
We elaborate on the suggestion made in arXiv:0806.3498 that the 3d \N=8
superconformal SU(N) Chern-Simons-matter theory of Lorentzian
Bagger-Lambert-Gustavson type (L-BLG) can be obtained by a scaling limit
(involving sending the level k to infinity and redefining the fields) from the
\N=6 superconformal U(N)xU(N) Chern-Simons-matter theory of Aharony, Bergman,
Jafferis and Maldacena (ABJM). We show that to implement such a limit in a
consistent way one is to extend the ABJM theory by an abelian "ghost"
multiplet. The corresponding limit at the 3-algebra level also requires
extending the non-antisymmetric Bagger-Lambert 3-algebra underlying the ABJM
theory by a negative-norm generator. We draw analogy with similar scaling
limits discussed previously for bosonic Chern-Simons theory and comment on some
implications of this relation between the ABJM and L-BLG theories.Comment: 16 pages; published version - reference added, minor correction
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