pinecone/core-2020-05-10-deduplication huggingface dataset:
Pp-wave Matrix Models from Point-like Gravitons

The BFSS Matrix model can be regarded as a theory of coincident M-theory
gravitons. In this spirit, we summarize how using the action for coincident
gravitons proposed in hep-th/0207199 it is possible to go beyond the linear
order approximation of Kabat and Taylor, and to provide a satisfactory
microscopical description of giant gravitons in $AdS_m\times S^n$ backgrounds.
We then show that in the M-theory maximally supersymmetric pp-wave background,
the action for coincident gravitons, besides reproducing the BMN Matrix model,
predicts a new quadrupolar coupling to the M-theory 6-form potential, which
supports the so far elusive fuzzy 5-sphere giant graviton solution. Finally, we
discuss similar Matrix models that can be derived in Type II string theories
using dualities.Comment: 7 pages, Talk presented by Y.L. at the RTN workshop, Napoli, Oct.
  9-13, 200
Supersymmetric D-branes on flux backgrounds

Several aspects concerning the physics of D-branes in Type II flux
compactifications preserving minimal N=1 supersymmetry in four dimensions are
considered. It is shown how these vacua are completely characterized in terms
of properly defined generalized calibrations for D-branes and the relation with
Generalized Complex Geometry is discussed. General expressions for
superpotentials and D-terms associated with the N=1 four-dimensional
description of space-time filling D-branes are presented. The massless spectrum
of calibrated D-branes can be characterized in terms of cohomology groups of a
differential complex canonically induced on the D-branes by the underlying
generalized complex structure.Comment: 9 pages; contribution to the proceedings of the RTN project
  `Constituents, Fundamental Forces and Symmetries of the Universe' conference
  in Napoli, October 9 - 13, 2006; (v2) references adde
BPS Solutions in AdS/CFT

We study a class of exact supersymmetric solutions of type IIB Supergravity.
They have an SO(4) x SU(2) x U(1) isometry and preserve generically 4 of the 32
supersymmetries of the theory. Asymptotically AdS_5 x S^5 solutions in this
class are dual to 1/8 BPS chiral operators which preserve the same symmetries
in the N=4 SYM theory. We analyse the solutions to these equations in a large
radius asymptotic expansion: they carry charges with respect to two U(1) KK
gauge fields and their mass saturates the expected BPS bound. We also show how
the same formalism is suitable for the description of the AdS_5 x Y^{p,q}
geometries and a class of their excitations.Comment: 5 pages, Latex, uses w-art class (included). To appear in the
  Proceedings of the RTN workshop "ForcesUniverse", Naples, October 9-13, 200
Entropy of Three-Charge Black Holes on a Circle

We study phases of five-dimensional three-charge black holes with a circle in
their transverse space. In particular, when the black hole is localized on the
circle we compute the corrections to the metric and corresponding
thermodynamics in the limit of small mass. When taking the near-extremal limit,
this gives the corrections to the finite entropy of the extremal three-charge
black hole as a function of the energy above extremality. For the partial
extremal limit with two charges sent to infinity and one finite we show that
the first correction to the entropy is in agreement with the microscopic
entropy by taking into account that the number of branes shift as a consequence
of the interactions across the transverse circle.Comment: 9 pages, 1 figure. Talk presented by NO at the RTN workshop, Napoli,
  Oct. 9-13, 200
The Hagedorn temperature in a decoupled sector of AdS/CFT

We match the Hagedorn/deconfinement temperature of planar N=4 super
Yang-Mills (SYM) on R x S^3 to the Hagedorn temperature of string theory on
AdS_5 x S^5. The match is done in a near-critical region where both gauge
theory and string theory are weakly coupled. On the gauge theory side we are
taking a decoupling limit found in hep-th/0605234 in which the physics of
planar N=4 SYM is given exactly by the ferromagnetic XXX_{1/2} Heisenberg spin
chain. We find moreover a general relation between the Hagedorn/deconfinement
temperature and the thermodynamics of the Heisenberg spin chain. On the string
theory side, we identify the dual limit which is taken of string theory on a
maximally symmetric pp-wave background with a flat direction, obtained from a
Penrose limit of AdS_5 x S^5. We compute the Hagedorn temperature of the string
theory and find agreement with the Hagedorn/deconfinement temperature computed
on the gauge theory side. Finally, we discuss a modified decoupling limit in
which planar N=4 SYM reduces to the XXX_{1/2} Heisenberg spin chain with an
external magnetic field.Comment: 7 pages. Talk presented by MO at the RTN workshop, Napoli, Oct. 9-13,
  200
Supersymmetry and cosmic censorship

We show that requiring unbroken supersymmetry everywhere in black-hole-type
solutions of N=2,d=4 supergravity coupled to vector supermultiplets ensures in
most cases absence of naked singularities. We show that the requirement of
global supersymmetry implies the absence of sources for NUT charge, angular
momentum, scalar hair and negative energy, for which there is no microscopic
interpretation in String Theory. These conditions exclude, for instance,
singular solutions such as the Kerr-Newman with M=|q|, which fails to be
everywhere supersymmetric. There are, nevertheless, everywhere supersymmetric
solutions with "global" angular momentum and non-trivial scalar fields. We also
present similar preliminary results in N=1,d=5 supergravity coupled to vector
multiplets.Comment: To be published in Talk given at the 2nd Workshop and Midterm Meeting
  of the Marie Curie RTN "Constituents, Fundamental Forces and Symmetries of
  the Universe", Naples, Italy, October 9-13 200
Microstates and near-horizon D-brane probes

In hep-th/0412322, Gaiotto, Strominger and Yin proposed a novel way of
counting black hole microstates by counting the quantum mechanical ground
states of probe branes placed in the near-horizon black hole background. We
discuss the generalization of this proposal to the case of two-charge D0-D4
`small' black holes in type IIA. We also describe the construction of BPS
D-brane probes in the near-horizon region of the 2-charge D1-D5 system in type
IIB. Based on hep-th/0505176, hep-th/0607150.Comment: 5 pages, contribution to the proceedings of the RTN project
  `Constituents, Fundamental Forces and Symmetries of the Universe' conference
  in Napoli, October 9 - 13, 200
Classification of supersymmetric backgrounds of string theory

We review the recent progress made towards the classification of
supersymmetric solutions in ten and eleven dimensions with emphasis on those of
IIB supergravity. In particular, the spinorial geometry method is outlined and
adapted to nearly maximally supersymmetric backgrounds. We then demonstrate its
effectiveness by classifying the maximally supersymmetric IIB G-backgrounds and
by showing that N=31 IIB solutions do not exist.Comment: 8 pages, contribution to the proceedings of the RTN project
  `Constituents, Fundamental Forces and Symmetries of the Universe' conference
  in Napoli, October 9 - 13, 200
The Stability of D-term Cosmic Strings

In this note, which is based on hep-th/0611111, we review the stability of
the static, positive deficit angle D-term string solutions of D=4, N=1
supergravity with a constant Fayet-Iliopoulos term. We prove the semi-classical
stability of this class of solutions using standard positive energy theorem
techniques. In particular, we discuss how the negative deficit angle D-term
string, which also solves the Killing spinor equations, violates the dominant
energy condition and so is excluded from our arguments.Comment: 9 pages, contribution to the proceedings of the RTN project
  `Constituents, Fundamental Forces and Symmetries of the Universe' conference
  in Napoli, October 9 - 13, 200
Gravitational theories coupled to matter as invariant theories under
  Kac-Moody algebras

Many recent researches indicate that several gravitational D-dimensional
theories suitably coupled to some matter fields (including in particular pure
gravity in D dimensions, the low energy effective actions of the bosonic string
and the bosonic sector of M-theory) would be characterized by infinite
dimensional Kac-Moody algebras G^{++} and G^{+++}. The possible existence of
these extended symmetries motivates a development of a new description of
gravitational theories based on these symmetries. The importance of Kac-Moody
algebras and the link between the G^{+++}-invariant theories and the
uncompactified space-time covariant theories are discussed.Comment: 7 pages, 1 figure, Contribution to the proceedings of the RTN project
  'Constituents, Fundamental Forces and Symmetries of the Universe' conference
  in Napoli, October 9-13, 200
Tensor supermultiplets and toric quaternion-Kahler geometry

We review the relation between 4n-dimensional quaternion-Kahler metrics with
n+1 abelian isometries and superconformal theories of n+1 tensor
supermultiplets. As an application we construct the class of eight-dimensional
quaternion-Kahler metrics with three abelian isometries in terms of a single
function obeying a set of linear second-order partial differential equations.Comment: 8 pages, Contribution to the proceedings of the RTN ForcesUniverse
  Network Workshop, Napoli, October 9th - 13th, 200
Consistent de Sitter String Vacua from Kahler Stabilization and D-term
  uplifting

In this note, we review our construction of de Sitter vacua in type IIB flux
compactifications, in which moduli stabilization and D-term uplifting can be
combined consistently with the supergravity constraints. Here, the closed
string fluxes fix the dilaton and the complex structure moduli while
perturbative quantum corrections to the K\"ahler potential stabilize the volume
Kahler modulus in an AdS_4-vacuum. Then, magnetized D7-branes provide
consistent supersymmetric D-term uplifting towards dS_4. Based on
hep-th/0602253.Comment: 8 pages, 1 figure, LaTeX, Contribution to the proceedings of the RTN
  project "Constituents, Fundamental Forces and Symmetries of the Universe"
  conference in Napoli, October 9-13, 200
Progress in D-brane model building

The state of the art in D-brane model building is briefly reviewed, focusing
on recent achievements in the construction of D=4 N = 1 type II string vacua
with semi-realistic gauge sectors. Such progress relies on a better
understanding of the spectrum of BPS D-branes, the effective field theory
obtained from them and the explicit construction of vacua. We first consider
D-branes in standard Calabi-Yau compactifications, and then the more involved
case of compactifications with fluxes. We discuss how the non-trivial interplay
between D-branes and fluxes modifies the previous model-building rules, as well
as provides new possibilities to connect string theory to particle physics.Comment: Using w-art.cls, 27 pages, 6 figures. Based on a talk given at the
  RTN `Constituents, Fundamental Forces and Symmetries of the Universe'
  Workshop and Midterm meeting in Napoli, October 2006. v2: typos corrected and
  references adde
Supersymmetric black holes in string theory

We review recent developments concerning supersymmetric black holes in string
theory. After a general introduction to the laws of black hole mechanics and to
black hole entropy in string theory, we discuss black hole solutions in N=2
supergravity, special geometry, the black hole attractor equations and the
underlying variational principle. Special attention is payed to the crucial
role of higher derivative corrections. Finally we discuss black hole partition
functions and their relation to the topological string, mainly from the
supergravity perspective. We try to summarize the state of art and discuss
various open questions and problems.Comment: 43 pages, based on a talk given at the midterm meeting of the RTN
  project `Constituents, Fundamental Forces and Symmetries of the Universe' in
  Naples, October 9-13, 200
N=1 domain wall solutions of massive type II supergravity and the issue
  of mirror symmetry

We report on Domain Wall solution of Calabi-Yau compactifications with
general fluxes and their application to the study of mirror symmetry in
generalized backgrounds. We address, in particular, to the issue of magnetic
NSNS fluxes. We show that the Domain Wall gradient flow equations can be
interpreted as a set of generalized Hitchin's flow equations of a manifold with
SU(3)x SU(3) structure fibered along the direction transverse to the Domain
wall.Comment: To appear in the proceedings of 2nd RTN Network Workshop and Midterm
  Meeting: Constituents, Fundamental Forces and Symmetries of the Universe,
  Naples, Italy, 9-13 Oct 200
Surface Operators and Knot Homologies

Topological gauge theories in four dimensions which admit surface operators
provide a natural framework for realizing homological knot invariants. Every
such theory leads to an action of the braid group on branes on the
corresponding moduli space. This action plays a key role in the construction of
homological knot invariants. We illustrate the general construction with
examples based on surface operators in N=2 and N=4 twisted gauge theories which
lead to a categorification of the Alexander polynomial, the equivariant knot
signature, and certain analogs of the Casson invariant.
  This paper is based on a lecture delivered at the International Congress on
Mathematical Physics 2006, Rio de Janeiro, and at the RTN Workshop 2006,
Napoli.Comment: 37 pages. Based on a talk given at the ICMP 2006 and at the RTN
  Workshop 200
Noncommutative Gravity and the *-Lie algebra of diffeomorphisms

We construct functions and tensors on noncommutative spacetime by
systematically twisting the corresponding commutative structures. The study of
the deformed diffeomorphisms (and Poincare) Lie algebra allows to construct a
noncomutative theory of gravity.Comment: 12 pages. Presented at the Erice International School of Subnuclear
  Physics, 44th course, Erice, Sicily, 29.8- 7.9 2006, and at the Second
  workshop and midterm meeting of the MCRTN ``Constituents, Fundamental Forces
  and Symmetries of the Universe" Napoli, 9-13.10 200
Gauged Supergravities in Various Spacetime Dimensions

In this review articel we study the gaugings of extended supergravity
theories in various space-time dimensions. These theories describe the
low-energy limit of non-trivial string compactifications. For each theory under
consideration we review all possible gaugings that are compatible with
supersymmetry. They are parameterized by the so-called embedding tensor which
is a group theoretical object that has to satisfy certain representation
constraints. This embedding tensor determines all couplings in the gauged
theory that are necessary to preserve gauge invariance and supersymmetry. The
concept of the embedding tensor and the general structure of the gauged
supergravities are explained in detail. The methods are then applied to the
half-maximal (N=4) supergravities in d=4 and d=5 and to the maximal
supergravities in d=2 and d=7. Examples of particular gaugings are given.
Whenever possible, the higher-dimensional origin of these theories is
identified and it is shown how the compactification parameters like fluxes and
torsion are contained in the embedding tensor.Comment: 155 pages, author's PhD thesi
Ensemble averaged coherent state path integral for disordered bosons
  with a repulsive interaction (Derivation of mean field equations)

We consider bosonic atoms with a repulsive contact interaction in a trap
potential for a Bose-Einstein condensation and additionally include a random
potential. The ensemble averages for two models of static and dynamic disorder
are performed and investigated in parallel. The bosonic many body systems of
the two disorder models are represented by coherent state path integrals on the
Keldysh time contour which allow exact ensemble averages for zero and finite
temperatures. These ensemble averages of coherent state path integrals
therefore present alternatives to replica field theories or supersymmetric
averaging techniques
Coherent state path integral and super-symmetry for condensates composed
  of bosonic and fermionic atoms

A super-symmetric coherent state path integral on the Keldysh time contour is
considered for bosonic and fermionic atoms which interact among each other with
a common short-ranged two-body potential. We investigate the symmetries of
Bose-Einstein condensation for the equivalent bosonic and fermionic
constituents and specialize on the examination of super-symmetries for pair
condensate terms. A Hubbard-Stratonovich transformation from 'Nambu'-doubled
super-fields leads to a generating function with super-matrices for the
self-energy whose manifold is given by the ortho-symplectic super-group
Osp(S,S|2L). Effective equations are derived for anomalous terms which are
related to the molecular- and BCS- condensate pairs. A change of integration
measure for the coset decomposition Osp(S,S|2L)/U(L|S)xU(L|S) is performed,
including a separation of density and anomalous parts of the self-energy with a
gradient expansion for the Goldstone modes. The independent anomalous fields in
the actions can be transformed by the inverse square root of the metric tensor
of Osp(S,S|2L)/U(L|S) so that the coset integration measure with the
super-Jacobi-determinant can be removed from the coherent state path integral
and Gaussian-like integrations remain. The variations of the independent coset
fields in the effective actions result in classical field equations for a
nonlinear sigma model with the anomalous terms
The Graviton Propagator with a Non-Conserved External Generating Source

A novel general expression is obtained for the graviton propagator from
Lagrangian field theory by taking into account the necessary fact that in the
functional differential approach of quantum field theory, in order to generate
non-linearities in gravitation and interactions with matter, the external
source $T_{\mu\nu}$, coupled to the gravitational field, should \textit{a
priori} not be conserved $\partial^\mu T_{\mu\nu}\neq 0$, so variations with
respect to its ten components may be varied \textit{independently}. The
resulting propagator is the one which arises in the functional approach and
does \textit{not} coincide with the corresponding time-ordered product of two
fields and it includes so-called Schwinger terms. The quantization is carried
out in a gauge corresponding to physical states with two polarization states to
ensure positivity in quantum applications.Comment: 12 page
Some Aspects of c=-2 Theory

We investigate some aspects of the c=-2 logarithmic conformal field theory.
These include the various representations related to this theory, the
structures which come out of the Zhu algebra and the W algebra related to this
theory. We try to find the fermionic representations of all of the fields in
the extended Kac table especially for the untwisted sector case. In addition,
we calculate the various OPEs of the fields, especially the energy-momentum
tensor. Moreover, we investigate the important role of the zero modes in this
model. We close the paper by considering the perturbations of this theory and
their relationship to integrable models and generalization of Zamolodchikov's
$c-$theorem.Comment: 25 page
Connecting String/M Theory to the Electroweak Scale and to LHC Data

The Standard Model of particle physics explains (almost) all observed
non-gravitational microscopic phenomena but has many open theoretical
questions. We are on the threshold of unraveling the mysteries of the Standard
Model and discovering its extension. This could be achieved in the near future
with the help of many experiments in particle physics and cosmology, the LHC in
particular. Assuming that data confirming the existence of new physics beyond
the Standard Model is obtained, one is left with the very important and
challenging task of solving the "Inverse Problem", \emph{viz.} "How can one
deduce the nature of the underlying (perhaps microscopic) theory from data?"
This thesis explores this question in detail, and also proposes an approach to
address the problem in a meaningful way which could prove crucial to the
possible solution to this problem in the future. The proposed approach has
three aspects - a) To systematically study classes of microscopic (string/$M$
theory) constructions to the extent that they could be connected to low energy
physics (electroweak scale), b) To find patterns of experimental observables
which are sensitive to the properties of the underlying theoretical
constructions thereby allowing us to distinguish among different constructions,
and c) To try to get insights about the qualitative features of the theoretical
model from data in a bottom-up approach which complements the top-down approach
and strengthens it as well. This thesis studies all the above aspects in
detail. The methods used and results obtained in this thesis will hopefully be
of great importance in solving the Inverse Problem.Comment: PhD Thesis, 320 pages, 63 figures References Adde
Optimised Dirac Operators on the Lattice: Construction, Properties and
  Applications

We review a number of topics related to block variable renormalisation group
transformations of quantum fields on the lattice, and to the emerging perfect
lattice actions. We first illustrate this procedure by considering scalar
fields. Then we proceed to lattice fermions, where we discuss perfect actions
for free fields, for the Gross-Neveu model and for a supersymmetric spin model.
We also consider the extension to perfect lattice perturbation theory, in
particular regarding the axial anomaly and the quark gluon vertex function.
Next we deal with properties and applications of truncated perfect fermions,
and their chiral correction by means of the overlap formula. This yields a
formulation of lattice fermions, which combines exact chiral symmetry with an
optimisation of further essential properties. We summarise simulation results
for these so-called overlap-hypercube fermions in the two-flavour Schwinger
model and in quenched QCD. In the latter framework we establish a link to
Chiral Perturbation Theory, both, in the p-regime and in the epsilon-regime. In
particular we present an evaluation of the leading Low Energy Constants of the
chiral Lagrangian - the chiral condensate and the pion decay constant - from
QCD simulations with extremely light quarks.Comment: published version (plus slight extension), 120 pages, 41 figure
Non-topological non-commutativity in string theory

Quantization of coordinates leads to the non-commutative product of deformation quantization, but is also at the roots of string theory, for which space-time coordinates become the dynamical fields of a two-dimensional conformal quantum field theory. Appositely, open string diagrams provided the inspiration for Kontsevich's solution of the long-standing problem of quantization of Poisson geometry by virtue of his formality theorem. In the context of D-brane physics non-commutativity is not limited, however, to the topolocial sector. We show that non-commutative effective actions still make sense when associativity is lost and establish a generalized Connes-Flato-Sternheimer condition through second order in a derivative expansion. The measure in general curved backgrounds is naturally provided by the Born--Infeld action and reduces to the symplectic measure in the topological limit, but remains non-singular even for degenerate Poisson structures. Analogous superspace deformations by RR--fields are also discussed
Spin Network Wavefunction and the Graviton Propagator

We show that if the flat-spacetime wavefunction in the spin network basis of
Loop Quantum Gravity has a large-spin asymptotics given by Rovelli's ansatz
then the corresponding graviton propagator has the correct large-distance
asymptotics nonperturbatively and independently of the spin foam model used to
describe the evolution operator. We also argue that even in the Rovelli
approach the wavefunction should satisfy the Hamiltonian constraint and we give
an explanation for the spin parameter appearing in Rovelli's ansatz.Comment: 8 page