3,008 research outputs found
Putting String/Fivebrane Duality to the Test
According to string/fivebrane duality, the Green-Schwarz factorization of the
spacetime anomaly polynomial into means that just
as is the anomaly polynomial of the string worldsheet so
should be the anomaly polynomial of the fivebrane worldvolume. To test
this idea we perform a fivebrane calculation of and find perfect
agreement with the string one--loop result.Comment: 14 pages, CERN TH-6614/92, CTP-TAMU 60/9
Quantum corrections to Higher-Dimensional Theories
This is a non-technical summary of the subtleties of quantum corrections on
extra-dimensional theories: should one first renormalize and then mode expand,
or first expand in four-dimensional modes and then renormalize?Comment: 9 pages, based on a talk at IRGAC 2006, Barcelon
Fundamental constants in effective theory
There is a discussion between L. B. Okun, G. Veneziano and M. J. Duff,
concerning the number of fundamental dimensionful constants in physics
(physics/0110060). They advocated correspondingly 3, 2 and 0 fundamental
constants. Here we consider this problem on example of the effective
relativistic quantum field theory, which emerges in the low energy corner of
quantum liquids and which reproduces many features of our physics including
chiral fermions, gauge fields and dynamical gravity.Comment: LaTeX file, 9 pages, version submitted to JETP Letter
Timelike Hopf Duality and Type IIA^* String Solutions
The usual T-duality that relates the type IIA and IIB theories compactified
on circles of inversely-related radii does not operate if the dimensional
reduction is performed on the time direction rather than a spatial one. This
observation led to the recent proposal that there might exist two further
ten-dimensional theories, namely type IIA^* and type IIB^*, related to type IIB
and type IIA respectively by a timelike dimensional reduction. In this paper we
explore such dimensional reductions in cases where time is the coordinate of a
non-trivial U(1) fibre bundle. We focus in particular on situations where there
is an odd-dimensional anti-de Sitter spacetime AdS_{2n+1}, which can be
described as a U(1) bundle over \widetilde{CP}^n, a non-compact version of CP^n
corresponding to the coset manifold SU(n,1)/U(n). In particular, we study the
AdS_5\times S^5 and AdS_7\times S^4 solutions of type IIB supergravity and
eleven-dimensional supergravity. Applying a timelike Hopf T-duality
transformation to the former provides a new solution of the type IIA^* theory,
of the form \widetilde{CP}^2\times S^1\times S^5. We show how the Hopf-reduced
solutions provide further examples of ``supersymmetry without supersymmetry.''
We also present a detailed discussion of the geometrical structure of the
Hopf-fibred metric on AdS_{2n+1}, and its relation to the horospherical metric
that arises in the AdS/CFT correspondence.Comment: Latex, 26 page
Vacuum interpolation in supergravity via super p-branes
We show that many of the recently proposed supersymmetric p-brane solutions
of d=10 and d=11 supergravity have the property that they interpolate between
Minkowski spacetime and a compactified spacetime, both being supersymmetric
supergravity vacua. Our results imply that the effective worldvolume action for
small fluctuations of the super p-brane is a supersingleton field theory for
, as has been often conjectured in the past.Comment: 8p
Twenty Years of the Weyl Anomaly
In 1973 two Salam prot\'{e}g\'{e}s (Derek Capper and the author) discovered
that the conformal invariance under Weyl rescalings of the metric tensor
displayed by classical
massless field systems in interaction with gravity no longer survives in the
quantum theory. Since then these Weyl anomalies have found a variety of
applications in black hole physics, cosmology, string theory and statistical
mechanics. We give a nostalgic review. (Talk given at the {\it Salamfest},
ICTP, Trieste, March 1993.)Comment: 43 page
A New Era in High-energy Physics
In TeV-scale gravity, scattering of particles with center-of-mass energy of
the order of a few TeV can lead to the creation of nonperturbative, extended,
higher-dimensional gravitational objects: Branes. Neutral or charged, spinning
or spinless, Einsteinian or supersymmetric, low-energy branes could
dramatically change our picture of high-energy physics. Will we create branes
in future particle colliders, observe them from ultra high energy cosmic rays,
and discover them to be dark matter?Comment: 8 pages, 2 figures. Essay submitted on Mar 26, 2002 to the Gravity
Research Foundation. Awarded the third prize in the 2002 GRF competitio
Tree Amplitudes and Two-loop Counterterms in D=11 Supergravity
We compute the tree level 4-particle bosonic scattering amplitudes in D=11
supergravity. By construction, they are part of a linearized supersymmetry-,
coordinate- and 3-form gauge-invariant. While this on-shell invariant is
nonlocal, suitable SUSY-preserving differentiations turn it into a local one
with correct dimension to provide a natural lowest (two-loop) order counterterm
candidate. Its existence shows explicitly that no symmetries protect this
ultimate supergravity from the nonrenormalizability of its lower-dimensional
counterparts.Comment: 14 page
The GS String Action on AdS(3)xS(3) with Ramond-Ramond Charge
We derive the classical kappa-symmetric Type IIB string action on AdS(3) x
S(3) by employing the SU(1,1|2)^2 algebra. We then gauge fix kappa-symmetry in
the background adapted Killing spinor gauge and present the action in a very
simple form.Comment: 19 pages, LaTe
Observations on Integral and Continuous U-duality Orbits in N=8 Supergravity
One would often like to know when two a priori distinct extremal black
p-brane solutions are in fact U-duality related. In the classical supergravity
limit the answer for a large class of theories has been known for some time.
However, in the full quantum theory the U-duality group is broken to a discrete
subgroup and the question of U-duality orbits in this case is a nuanced matter.
In the present work we address this issue in the context of N=8 supergravity in
four, five and six dimensions. The purpose of this note is to present and
clarify what is currently known about these discrete orbits while at the same
time filling in some of the details not yet appearing in the literature. To
this end we exploit the mathematical framework of integral Jordan algebras and
Freudenthal triple systems. The charge vector of the dyonic black string in D=6
is SO(5,5;Z) related to a two-charge reduced canonical form uniquely specified
by a set of two arithmetic U-duality invariants. Similarly, the black hole
(string) charge vectors in D=5 are E_{6(6)}(Z) equivalent to a three-charge
canonical form, again uniquely fixed by a set of three arithmetic U-duality
invariants. The situation in four dimensions is less clear: while black holes
preserving more than 1/8 of the supersymmetries may be fully classified by
known arithmetic E_{7(7)}(Z) invariants, 1/8-BPS and non-BPS black holes yield
increasingly subtle orbit structures, which remain to be properly understood.
However, for the very special subclass of projective black holes a complete
classification is known. All projective black holes are E_{7(7)}(Z) related to
a four or five charge canonical form determined uniquely by the set of known
arithmetic U-duality invariants. Moreover, E_{7(7)}(Z) acts transitively on the
charge vectors of black holes with a given leading-order entropy.Comment: 43 pages, 8 tables; minor corrections, references added; version to
appear in Class. Quantum Gra
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