951 research outputs found
A Kaluza-Klein inspired action for chiral p-forms and their anomalies
The dynamics of chiral p-forms can be captured by a lower-dimensional
parity-violating action motivated by a Kaluza-Klein reduction on a circle. The
massless modes are (p-1)-forms with standard kinetic terms and Chern-Simons
couplings to the Kaluza-Klein vector of the background metric. The massive
modes are p-forms charged under the Kaluza-Klein vector and admit parity-odd
first-order kinetic terms. Gauge invariance is implemented by a
Stueckelberg-like mechanism using (p-1)-forms. A Chern-Simons term for the
Kaluza-Klein vector is generated at one loop by massive p-form modes. These
findings are shown to be consistent with anomalies and supersymmetry for
six-dimensional supergravity theories with chiral tensor multiplets.Comment: 4 pages, 1 figur
Mersenne Primes, Polygonal Anomalies and String Theory Classification
It is pointed out that the Mersenne primes and associated
perfect numbers play a significant role in string
theory; this observation may suggest a classification of consistent string
theories.Comment: 10 pages LaTe
Aspects of ALE Matrix Models and Twisted Matrix Strings
We examine several aspects of the formulation of M(atrix)-Theory on ALE
spaces. We argue for the existence of massless vector multiplets in the
resolved spaces, as required by enhanced gauge symmetry in M-Theory,
and that these states might have the correct gravitational interactions. We
propose a matrix model which describes M-Theory on an ALE space in the presence
of wrapped membranes. We also consider orbifold descriptions of matrix string
theories, as well as more exotic orbifolds of these models, and present a
classification of twisted matrix string theories according to Reid's exact
sequences of surface quotient singularities.Comment: 27 pages LaTeX2e, 7 figures, using utarticle.cls (included),
array.sty, amsmath.sty, amsfonts.sty, cite.sty, epsf.sty. Bibtex style:
utphys.bst (.bbl file included). Section on wrapped membrane states revised
and expanded. We now argue for the existence of wrapped membranes and propose
a matrix model which describes M-Theory on an ALE space in the presence of
wrapped membrane
BPS Solitons in M5-Brane Worldvolume Theory with Constant Three-Form Field
We study BPS solutions for a self-dual string and a neutral string in
M5-brane worldvolume theory with constant three-form field. We further
generalize such solitons to superpose with a calibrated surface. We also study
a traveling wave on a calibrated surface in the constant three-form field
background.Comment: 12 pages, LaTeX, minor correction, added referenc
Type IIB Matrix Theory at Two Loops
The IKKT matrix model was proposed to be a non-perturbative formulation of
type IIB superstring theory. One of its important consistency criteria is that
the leading one-loop effective interaction between a cluster of type
IIB D-objects should not receive any corrections from higher loop effects for
it to describe accurately the type IIB supergravity results. In analogy with
the BFSS matrix model {\it versus} the eleven-dimensional supergravity example,
we show in this work that the one-loop effective potential in the IKKT matrix
model is also not renormalized at the two-loop order.Comment: 19 pages, Latex, corrected some typos and 1 figure adde
Supermembranes and Super Matrix Models
We review recent developments in the theory of supermembranes and their
relation to matrix models.Comment: Invited lecture presented at the Corfu Workshop, September 20 - 26,
1998, of the TMR Project "Quantum Aspects of Gauge Theories, Supersymmetry
and Unification" (ERBFMRXCT96-0045), to appear in the proceedings. Latex 41
p
Fluxes and Warping for Gauge Couplings in F-theory
We compute flux-dependent corrections in the four-dimensional F-theory
effective action using the M-theory dual description. In M-theory the 7-brane
fluxes are encoded by four-form flux and modify the background geometry and
Kaluza-Klein reduction ansatz. In particular, the flux sources a warp factor
which also depends on the torus directions of the compactification fourfold.
This dependence is crucial in the derivation of the four-dimensional action,
although the torus fiber is auxiliary in F-theory. In M-theory the 7-branes are
described by an infinite array of Taub-NUT spaces. We use the explicit metric
on this geometry to derive the locally corrected warp factor and M-theory
three-from as closed expressions. We focus on contributions to the 7-brane
gauge coupling function from this M-theory back-reaction and show that terms
quadratic in the internal seven-brane flux are induced. The real part of the
gauge coupling function is modified by the M-theory warp factor while the
imaginary part is corrected due to a modified M-theory three-form potential.
The obtained contributions match the known weak string coupling result, but
also yield additional terms suppressed at weak coupling. This shows that the
completion of the M-theory reduction opens the way to compute various
corrections in a genuine F-theory setting away from the weak string coupling
limit.Comment: 46 page
Radiation from Accelerated Branes
The radiation emitted by accelerated fundamental strings and D-branes is
studied within the linear approximation to the supergravity limit of string
theory. We show that scalar, gauge field and gravitational radiation is
generically emitted by such branes. In the case where an external scalar field
accelerates the branes, we derive a Larmor-type formula for the emitted scalar
radiation and study the angular distribution of the outgoing energy flux. The
classical radii of the branes are calculated by means of the corresponding
Thompson scattering cross sections. Within the linear approximation, the
interaction of the external scalar field with the velocity fields of the branes
gives a contribution to the observed gauge field and gravitational radiation.Comment: LaTeX, 25 pages, 2 figures; v2: added comments on the validity of the
linear approximation, minor changes; version to appear in Physical Review
Gauge Theory and the Excision of Repulson Singularities
We study brane configurations that give rise to large-N gauge theories with
eight supersymmetries and no hypermultiplets. These configurations include a
variety of wrapped, fractional, and stretched branes or strings. The
corresponding spacetime geometries which we study have a distinct kind of
singularity known as a repulson. We find that this singularity is removed by a
distinctive mechanism, leaving a smooth geometry with a core having an enhanced
gauge symmetry. The spacetime geometry can be related to large-N Seiberg-Witten
theory.Comment: 31 pages LaTeX, 2 figures (v3: references added
- …