pinecone/core-2020-05-10-deduplication huggingface dataset:
Gravity with de Sitter and Unitary Tangent Groups

Einstein Gravity can be formulated as a gauge theory with the tangent space
respecting the Lorentz symmetry. In this paper we show that the dimension of
the tangent space can be larger than the dimension of the manifold and by
requiring the invariance of the theory with respect to 5d Lorentz group (de
Sitter group) Einstein theory is reproduced unambiguously. The other
possibility is to have unitary symmetry on a complex tangent space of the same
dimension as the manifold. In this case the resultant theory is
Einstein-Strauss Hermitian gravity. The tangent group is important for matter
couplings. We show that in the de Sitter case the 4 dimensional space time
vector and scalar are naturally unified by a hidden symmetry being components
of a 5d vector in the tangent space. With a de Sitter tangent group spinors can
exist only when they are made complex or taken in doublets in a way similar to
N=2 supersymmetry.Comment: 23 pages, one reference added.To be published in JHE
The Grassmannian Origin Of Dual Superconformal Invariance

A dual formulation of the S Matrix for N=4 SYM has recently been presented,
where all leading singularities of n-particle N^{k-2}MHV amplitudes are given
as an integral over the Grassmannian G(k,n), with cyclic symmetry, parity and
superconformal invariance manifest. In this short note we show that the dual
superconformal invariance of this object is also manifest. The geometry
naturally suggests a partial integration and simple change of variable to an
integral over G(k-2,n). This change of variable precisely corresponds to the
mapping between usual momentum variables and the "momentum twistors" introduced
by Hodges, and yields an elementary derivation of the momentum-twistor space
formula very recently presented by Mason and Skinner, which is manifestly dual
superconformal invariant. Thus the G(k,n) Grassmannian formulation allows a
direct understanding of all the important symmetries of N=4 SYM scattering
amplitudes.Comment: 9 page
M5 spikes and operators in the HVZ membrane theory

In this note we study some aspects of the so-called dual ABJM theory
introduced by Hanany, Vegh & Zaffaroni. We analyze the spectrum of chiral
operators, and compare it with the spectrum of functions on the mesonic moduli
space M=C^2\times C^2/Z_k, finding expected agreement for the coherent branch.
A somewhat mysterious extra branch of dimension N^2 opens up at the orbifold
fixed point. We also study BPS solutions which represent M2/M5 intersections.
The mesonic moduli space suggests that there should be two versions of this
spike: one where the M5 lives in the orbifolded C^2 and another where it lives
in the unorbifolded one. While expectedly the first class turns out to be like
the ABJM spike, the latter class looks like a collection of stacks of M5 branes
with fuzzy S^3 profiles. This shows hints of the appearance of the global SO(4)
at the non-abelian level which is otherwise not present in the bosonic
potential. We also study the matching of SUGRA modes with operators in the
coherent branch of the moduli space. As a byproduct, we present some formulae
for the laplacian in conical CY_4 of the form C^n\times CY_{4-n}.Comment: 22 pages, 1 figure. Published version with corrected typos
Pointlike probes of superstring-theoretic superfluids

In analogy with an experimental setup used in liquid helium, we use a
pointlike probe to study superfluids which have a gravity dual. In the gravity
description, the probe is represented by a hanging string. We demonstrate that
there is a critical velocity below which the probe particle feels neither drag
nor stochastic forces. Above this critical velocity, there is power-law scaling
for the drag force, and the stochastic forces are characterized by a finite,
velocity-dependent temperature. This temperature participates in two simple and
general relations between the drag force and stochastic forces. The formula we
derive for the critical velocity indicates that the low-energy excitations are
massless, and they demonstrate the power of stringy methods in describing
strongly coupled superfluids.Comment: 17 pages, 2 figures, added a figure, a reference, and moved material
  to an appendi
Higher Derivative Corrections to R-charged Black Holes: Boundary
  Counterterms and the Mass-Charge Relation

We carry out the holographic renormalization of Einstein-Maxwell theory with
curvature-squared corrections. In particular, we demonstrate how to construct
the generalized Gibbons-Hawking surface term needed to ensure a perturbatively
well-defined variational principle. This treatment ensures the absence of ghost
degrees of freedom at the linearized perturbative order in the
higher-derivative corrections. We use the holographically renormalized action
to study the thermodynamics of R-charged black holes with higher derivatives
and to investigate their mass to charge ratio in the extremal limit. In five
dimensions, there seems to be a connection between the sign of the higher
derivative couplings required to satisfy the weak gravity conjecture and that
violating the shear viscosity to entropy bound. This is in turn related to
possible constraints on the central charges of the dual CFT, in particular to
the sign of c-a.Comment: 30 pages. v2: references added, some equations simplifie
Hitchin Equation, Singularity, and N=2 Superconformal Field Theories

We argue that Hitchin's equation determines not only the low energy effective
theory but also describes the UV theory of four dimensional N=2 superconformal
field theories when we compactify six dimensional $A_N$ $(0,2)$ theory on a
punctured Riemann surface. We study the singular solution to Hitchin's equation
and the Higgs field of solutions has a simple pole at the punctures; We show
that the massless theory is associated with Higgs field whose residual is a
nilpotent element; We identify the flavor symmetry associated with the puncture
by studying the singularity of closure of the moduli space of solutions with
the appropriate boundary conditions. For the mass-deformed theory the residual
of the Higgs field is a semi-simple element, we identify the semi-simple
element by arguing that the moduli space of solutions of mass-deformed theory
must be a deformation of the closure of the moduli space of the massless
theory. We also study the Seiberg-Witten curve by identifying it as the
spectral curve of the Hitchin's system. The results are all in agreement with
Gaiotto's results derived from studying the Seiberg-Witten curve of four
dimensional quiver gauge theory.Comment: 42 pages, 20 figures, Hitchin's equation for N=2 theory is derived by
  comparing different order of compactification of six dimensional theory on
  T^2\times \Sigma. More discussion about flavor symmetries. Typos are
  correcte
Supergravity Solutions from Floating Branes

We solve the equations of motion of five-dimensional ungauged supergravity
coupled to three U(1) gauge fields using a floating-brane Ansatz in which the
electric potentials are directly related to the gravitational warp factors. We
find a new class of non-BPS solutions, that can be obtained linearly starting
from an Euclidean four-dimensional Einstein-Maxwell base. This class - the
largest known so far - reduces to the BPS and almost-BPS solutions in certain
limits. We solve the equations explicitly when the base space is given by the
Israel-Wilson metric, and obtain solutions describing non-BPS D6 and anti-D6
branes kept in equilibrium by flux. We also examine the action of spectral flow
on solutions with an Israel-Wilson base and show that it relates these
solutions to almost-BPS solutions with a Gibbons-Hawking base.Comment: 24 pages, 1 figur
From Matrices to Strings and Back

We discuss an explicit construction of a string dual for the Gaussian matrix
model. Starting from the matrix model and employing Strebel differential
techniques we deduce hints about the structure of the dual string. Next,
following these hints a worldheet theory is constructed. The correlators in
this string theory are assumed to localize on a finite set of points in the
moduli space of Riemann surfaces. To each such point one associates a Feynman
diagram contributing to the correlator in the dual matrix model, and thus
recasts the worldsheet expression as a sum over Feynman diagrams.Comment: 27 pages, 3 figure
Transformations of triangle ladder diagrams

It is shown how dual space diagrammatic representation of momentum integrals
corresponding to triangle ladder diagrams with an arbitrary number of rungs can
be transformed to half-diamonds. In paper arXiv:0803.3420 [hep-th] the
half-diamonds were related by conformal integral substitution to the diamonds
which represent the dual space image of four-point ladder integrals in the
four-dimensional momentum space. Acting in the way described in the present
paper we do not need to use the known result for diamond (four-point) diagrams
as an external input in deriving relations of arXiv:0803.3420 [hep-th],
however, that result for the diamond diagram arises in the present proof as an
intermediate consequence in a step-by-step diagrammatic transformation from the
triangle ladder diagram to the half-diamond diagrams.Comment: 12 pages, 14 figures, Talk at "High energy physics in the LHC era"
  conference, Valparaiso,Chile, The XVIIth Oporto Meeting on Geometry, Topology
  and Physics "Mathematical aspects of quantum field theory", Oporto, Portugal;
  Revised version, Section 4 is enlarged, last paragraph in Conclusion is new,
  references added, second paragraph in Introduciton is modifie
Phenomenological Aspects of Gauge Mediation with Sequestered
  Supersymmetry Breaking in light of Dark Matter Detection

In a recent work, a model of gauge mediation with sequestered supersymmetry
(SUSY) breaking was proposed. In this model, the mass of the gravitino is
O(100) GeV without causing the flavor-changing neutral-current problem. In
contrast to traditional gauge mediation, the gravitino is not the lightest SUSY
particle and the neutralino is the candidate of the dark matter. In this paper,
we investigate phenomenological aspects of this model and discuss the
possibility of the direct detection of the dark matter. In particular, we focus
on the light neutralino case and find that the light-Higgsino scenario such as
the focus point is interesting, taking account of the recent CDMS result.Comment: 17 pages, 8 figures; v2:references added, some corrections;
  v3:version accepted for publication in JHE
Early search for supersymmetric dark matter models at the LHC without
  missing energy

We investigate early discovery signals for supersymmetry at the Large Hadron
Collider without using information about missing transverse energy. Instead we
use cuts on the number of jets and isolated leptons (electrons and/or muons).
We work with minimal supersymmetric extensions of the standard model, and focus
on phenomenological models that give a relic density of dark matter compatible
with the WMAP measurements. An important model property for early discovery is
the presence of light sleptons, and we find that for an integrated luminosity
of only 200--300 pb$^{-1}$ at a center-of-mass energy of 10 TeV models with
gluino masses up to $\sim 700$ GeV can be tested.Comment: 28 pages, 12 figures; published versio
A Study of Wall-Crossing: Flavored Kinks in D=2 QED

We study spectrum of D=2 N=(2,2) QED with N+1 massive charged chiral
multiplets, with care given to precise supermultiplet countings. In the
infrared the theory flows to CP^N model with twisted masses, where we construct
generic flavored kink solitons for the large mass regime, and study their
quantum degeneracies. These kinks are qualitatively different and far more
numerous than those of small mass regime, with features reminiscent of
multi-pronged (p,q) string web, complete with the wall-crossing behavior. It
has been also conjectured that spectrum of this theory is equivalent to the
hypermultiplet spectrum of a certain D=4 Seiberg-Witten theory. We find that
the correspondence actually extends beyond hypermultiplets in D=4, and that
many of the relevant indices match. However, a D=2 BPS state is typically
mapped to several different kind of dyons whose individual supermultiplets are
rather complicated; the match of index comes about only after summing over
indices of these different dyons. We note general wall-crossing behavior of
flavored BPS kink states, and compare it to those of D=4 dyons.Comment: 47 pages, 5 figures; typos fixed; references adde
Toward Thermalization in Heavy Ion Collisions at Strong Coupling

We find the trapped surface for a collision of two sourceless shock waves in
AdS$_5$ and conclude that such collisions always lead to a creation of a black
hole in the bulk. Due to holographic correspondence, in the boundary gauge
theory this result proves that a thermalized medium (quark-gluon plasma) is
produced in heavy ion collisions at strong coupling (albeit in ${\cal N} =4$
super-Yang-Mills theory). We present new evidence supporting the analytic
estimate for the time of thermalization that exists in the literature and find
that thermalization time is parametrically much shorter than the time of shock
wave stopping, indicating that our result may be relevant for description of
heavy ion collision experiments.Comment: 23 pages, 2 figures; v2: typos corrected, references added, version
  accepted for publication in JHE
Integrability and the AdS(3)/CFT(2) correspondence

We investigate the AdS(3)/CFT(2) correspondence for theories with 16
supercharges using the integrability approach. We construct Green-Schwarz
actions for Type IIB strings on AdS(3)xS(3)xM(4) where M(4)=T(4) or S(3)xS(1)
using the coset approach. These actions are based on a Z(4) automorphism of the
super-coset D(2,1;alpha)xD(2,1;alpha)/SO(1,2)xSO(3)xSO(3). The equations of
motion admit a representation in terms of a Lax connection, showing that the
system is classically integrable. We present the finite gap equations for these
actions. When alpha=0,1/2,1 we propose a set of quantum Bethe equations valid
at all values of the coupling. The AdS(3)/CFT(2) duals contain novel massless
modes whose role remains to be explored.Comment: 43 pages, 4 figures; v2: misprints corrected; v3: clarifications on
  validity of quantum Bethe equations added in sec. 7.4, misprints correcte
Dileptonic signatures of T-odd quarks at the LHC

Little Higgs models are often endowed with a T-parity in order to satisfy
electroweak precision tests and give at the same time a stable particle which
is a candidate for cold dark matter. This type of models predicts a set of new
T-odd fermions in addition to the heavy gauge bosons of the Little Higgs
models, which may show interesting signatures at colliders. In this paper, we
study the signatures of strong and electroweak pair production of the first two
generations of T-odd quarks at the LHC. We focus on the dileptonic signatures
(p p to l l j j MET) with (a) opposite-sign dileptons and (b) same-sign
dileptons.Comment: 19 pages, 15 figure
Open Worldsheets for Holographic Interfaces

Type IIB supergravity admits Janus and multi-Janus solutions with eight
unbroken supersymmetries that are locally asymptotic to AdS_3 x S^3 x M_4
(where M_4 is either T^4 or K_3). These solutions are dual to two or more CFTs
defined on half-planes which share a common line interface. Their geometry
consists of an AdS_2 x S^2 x M_4 fibration over a simply connected Riemann
surface Sigma with boundary.
  In the present paper, we show that regular exact solutions exist also for
surfaces Sigma which are not simply connected. Specifically, we construct in
detail solutions for which Sigma has the topology of an annulus. This
construction is generalized to produce solutions for any surface Sigma with the
topology of an open string worldsheet with g holes.Comment: pdflatex, 43 pages, 6 figures, v2: minor correction
Pathological behaviour of the scalar graviton in Ho\v{r}ava-Lifshitz
  gravity

We confirm the recent claims that, in the infrared limit of
Ho\v{r}ava-Lifshitz gravity, the scalar graviton becomes a ghost if the sound
speed squared is positive on the flat de Sitter and Minkowski background. In
order to avoid the ghost and tame the instability, the sound speed squared
should be negative and very small, which means that the flow parameter
$\lambda$ should be very close to its General Relativity (GR) value. We
calculate the cubic interactions for the scalar graviton which are shown to
have a similar structure with those of the curvature perturbation in
k-inflation models. The higher order interactions become increasing important
for a smaller sound speed squared, that is, when the theory approaches GR. This
invalidates any linearized analysis and any predictability is lost in this
limit as quantum corrections are not controllable. This pathological behaviour
of the scalar graviton casts doubt on the validity of the projectable version
of the theory.Comment: 7 pages, references added; v3: Typos corrected, minor changes to text
  and precise determination of the strong coupling scale. Replaced to match
  published version
Deformations of Lifshitz holography

The simplest gravity duals for quantum critical theories with z=2 `Lifshitz'
scale invariance admit a marginally relevant deformation. Generic black holes
in the bulk describe the field theory with a dynamically generated momentum
scale Lambda as well as finite temperature T. We describe the thermodynamics of
these black holes in the quantum critical regime where T >> Lambda^2. The
deformation changes the asymptotics of the spacetime mildly and leads to
intricate UV sensitivities of the theory which we control perturbatively in
Lambda^2/T.Comment: 1+27 pages, 12 figure
Essentials of Blackfold Dynamics

We develop and significantly generalize the effective worldvolume theory for
higher-dimensional black holes recently proposed by the authors. The theory,
which regards the black hole as a black brane curved into a submanifold of a
background spacetime -a blackfold-, can be formulated in terms of an effective
fluid that lives on a dynamical worldvolume. Thus the blackfold equations split
into intrinsic (fluid-dynamical) equations, and extrinsic (generalized geodesic
embedding) equations. The intrinsic equations can be easily solved for
equilibrium configurations, thus providing an efficient formalism for the
approximate construction of novel stationary black holes. Furthermore, it is
possible to study time evolution. In particular, the long-wavelength component
of the Gregory-Laflamme instability of black branes is obtained as a sound-mode
instability of the effective fluid. We also discuss action principles,
connections to black hole thermodynamics, and other consequences and possible
extensions of the approach. Finally, we outline how the fluid/AdS-gravity
correspondence is related to this formalism.Comment: 37 pages, v2 minor comments and a reference adde
Gauge-Higgs Dark Matter

When the anti-periodic boundary condition is imposed for a bulk field in
extradimensional theories, independently of the background metric, the lightest
component in the anti-periodic field becomes stable and hence a good candidate
for the dark matter in the effective 4D theory due to the remaining accidental
discrete symmetry. Noting that in the gauge-Higgs unification scenario,
introduction of anti-periodic fermions is well-motivated by a phenomenological
reason, we investigate dark matter physics in the scenario. As an example, we
consider a five-dimensional SO(5)$\timesU(1)_X$ gauge-Higgs unification model
compactified on the $S^1/Z_2$ with the warped metric. Due to the structure of
the gauge-Higgs unification, interactions between the dark matter particle and
the Standard Model particles are largely controlled by the gauge symmetry, and
hence the model has a strong predictive power for the dark matter physics.
Evaluating the dark matter relic abundance, we identify a parameter region
consistent with the current observations. Furthermore, we calculate the elastic
scattering cross section between the dark matter particle and nucleon and find
that a part of the parameter region is already excluded by the current
experimental results for the direct dark matter search and most of the region
will be explored in future experiments.Comment: 16 pages, 2 figure
Composite Vectors at the Large Hadron Collider

An unspecified strong dynamics may give rise to composite vectors
sufficiently light that their interactions, among themselves or with the
electroweak gauge bosons, be approximately described by an effective Lagrangian
invariant under $SU(2)_L\times SU(2)_R/ SU(2)_{L+R}$. We study the production
at the LHC of two such states by vector boson fusion or by the Drell--Yan
process in this general framework and we compare it with the case of gauge
vectors from a $SU(2)_L\times SU(2)_R\times SU(2)^N$ gauge model spontaneously
broken to the diagonal SU(2) subgroup by a generic $\sigma$-model. Special
attention is payed to the asymptotic behaviour of the different amplitudes in
both cases. The expected rates of multi-lepton events from the decay of the
composite vectors are also given. A thorough phenomenological analysis and the
evaluation of the backgrounds to such signals, aiming at assessing the
visibility of composite-vector pairs at the LHC, is instead deferred to future
work.Comment: 17 pages, 4 figures, 2 table
Tree-level unitarity in Gauge-Higgs Unification

We numerically estimate a scale $\Lambda_{uni}$ at which tree-level unitarity
is violated in the $SO(5)\times U(1)_X$ gauge-Higgs unification model by
evaluating amplitudes for scattering of the longitudinal W bosons. The
scattering amplitudes take larger values in the warped spacetime than in the
flat spacetime, and take maximal values when $\theta_H=\pi/2$, where $\theta_H$
is the Wilson line phase along the extra dimension. We take into account not
only the elastic scattering but also possible inelastic scatterings in order to
estimate $\Lambda_{\rm uni}$. We found that $\Lambda_{\rm uni}\simeq 1.3m_{KK}$
in the warped spacetime, and $\Lambda_{\rm uni}\simeq 140m_{KK}$ in the flat
spacetime, where $m_{KK}$ is the Kaluza-Klein mass scale. The tree-level
unitarity is violated at $O(1TeV)$ for $\theta_H=\pi/2$ in the former case due
to the vanishing WWH coupling.Comment: 37 pages, 9 figures, some comments adde
Twistor-Strings, Grassmannians and Leading Singularities

We derive a systematic procedure for obtaining an explicit, L-loop leading
singularities of planar N=4 super Yang-Mills scattering amplitudes in twistor
space directly from their momentum space channel diagrams. The expressions are
given as integrals over the moduli of connected, nodal curves in twistor space
whose degree and genus matches expectations from twistor-string theory. We
propose that a twistor-string theory for pure N=4 super Yang-Mills, if it
exists, is determined by the condition that these leading singularity formulae
arise as residues when an unphysical contour for the path integral is used, by
analogy with the momentum space leading singularity conjecture. We go on to
show that the genus g twistor-string moduli space for g-loop N^{k-2}MHV
amplitudes may be mapped into the Grassmannian G(k,n). Restricting to a leading
singularity, the image of this map is a 2(n-2)-dimensional subcycle of G(k,n)
of exactly the type found from the Grassmannian residue formula of
Arkani-Hamed, Cachazo, Cheung and Kaplan. Based on this correspondence and the
Grassmannian conjecture, we deduce restrictions on the possible leading
singularities of multi-loop N^pMHV amplitudes. In particular, we argue that no
new leading singularities can arise beyond 3p loops.Comment: 50 pages, 20 figures. Section 2.5 extended, errors in 5.2 corrected,
  new section 5.3 inserted, references added. In all, 5 new diagrams and 5
  extra page