pinecone/core-2020-05-10-deduplication huggingface dataset:
Loop corrections to the antibrane potential

Antibranes provide some of the most generic ways to uplift Anti-de Sitter
flux compactifications to de Sitter, and there is a growing body of evidence
that antibranes placed in long warped throats such as the Klebanov-Strassler
warped deformed conifold solution have a brane-brane-repelling tachyon. This
tachyon was first found in the regime of parameters in which the backreaction
of the antibranes is large, and its existence was inferred from a highly
nontrivial cancellation of certain terms in the inter-brane potential. We use a
brane effective action approach, similar to that proposed by Michel, Mintun,
Polchinski, Puhm and Saad in arXiv:1412.5702, to analyze antibranes in
Klebanov-Strassler when their backreaction is small, and find a regime of
parameters where all perturbative contributions to the action can be computed
explicitly. We find that the cancellation found at strong coupling is also
present in the weak-coupling regime, and we establish its existence to all
loops. Our calculation indicates that the spectrum of the antibrane worldvolume
theory is not gapped, and may generically have a tachyon. Hence uplifting
mechanisms involving antibranes remain questionable even when backreaction is
small.Comment: 27 pages, 5 figures, v2: Added clarification of statements, version
  accepted for publication in JHE
Orientifolds of Warped Throats from Toric Calabi-Yau Singularities

We study the complex deformations of orientifolds of D3-branes at toric CY
singularities, using their description in terms of dimer diagrams. We describe
orientifold quotients that have fixed lines or fixed points in the dimer, and
characterize the possibilities to deform them in terms of the behaviour of
zig-zag paths under the orientifold symmetry. The resulting models are
holographic duals to warped throats with orientifold planes. Our systematic
construction provides a general class of configurations which includes models
recently appeared in the context of de Sitter uplift by nilpotent goldstino or
dynamical supersymmetry breaking.Comment: 39 pages, 23 figures. v2: minor corrections don
Precision Drell-Yan Measurements at the LHC and Implications for the
  Diphoton Excess

Precision measurements of the Drell-Yan (DY) cross section at the LHC
constrain new physics scenarios that involve new states with electroweak (EW)
charges. We analyze these constraints and apply them to models that can address
the LHC diphoton excess at 750 GeV. We confront these findings with LEP EW
precision tests and show that DY provides stronger constraints than the LEP
data. While 8 TeV data can already probe some parts of the interesting region
of parameter space, LHC14 results are expected to cover a substantial part of
the relevant terrain. We derive the bounds from the existing data, estimate
LHC14 reach and compare them to the bounds one gets from LEP and future FCC-ee
precision measurements.Comment: 21 pages, 7 figures; v2: minor change
Vacua of the gravitational field

The Poincar\'e invariant vacuum is not unique in quantum gravity. The BMS
supertranslation symmetry originally defined at null infinity is spontaneously
broken and results in inequivalent Poincar\'e vacua. In this paper we construct
the unique vacua which interpolate between past and future null infinity in BMS
gauge and which are entirely characterized by an arbitary Goldstone boson
defined on the sphere which breaks BMS invariance. We show that these vacua
contain a defect which carries no Poincar\'e charges but which generically
carries superrotation charges. We argue that there is a huge degeneracy of
vacua with multiple defects. We also present the single defect vacua with its
canonically conjugated source which can be constructed from a Liouville boson
on the stereographic plane. We show that positivity of the energy forces the
stress-tensor of the boson to vanish as a boundary condition. Finite
superrotations, which turn on the sources, are therefore physically ruled out
as canonical transformations around the vacua. Yet, infinitesimal
superrotations are external symplectic symmetries which are associated with
conserved charges which characterize the Goldstone boson.Comment: Accepted in JHEP, comments added, 34 page
Two-dimensional RCFT's without Kac-Moody symmetry

Using the method of modular-invariant differential equations, we classify a
family of Rational Conformal Field Theories with two and three characters
having no Kac-Moody algebra. In addition to unitary and non-unitary minimal
models, we find "dual" theories whose characters obey bilinear relations with
those of the minimal models to give the Moonshine Module. In some ways this
relation is analogous to cosets of meromorphic CFT's. The theory dual in this
sense to the Ising model has central charge 47/2 and is related to the Baby
Monster Module.Comment: 18 page
An Investigation of AdS$_2$ Backreaction and Holography

We investigate a dilaton gravity model in AdS$_2$ proposed by Almheiri and
Polchinski and develop a 1d effective description in terms of a dynamical
boundary time with a Schwarzian derivative action. We show that the effective
model is equivalent to a 1d version of Liouville theory, and investigate its
dynamics and symmetries via a standard canonical framework. We include the
coupling to arbitrary conformal matter and analyze the effective action in the
presence of possible sources. We compute commutators of local operators at
large time separation, and match the result with the time shift due to a
gravitational shockwave interaction. We study a black hole evaporation process
and comment on the role of entropy in this model.Comment: 32 pages, 6 figures, v3: typos corrected and references added,
  matches published versio
A Conformal Truncation Framework for Infinite-Volume Dynamics

We present a new framework for studying conformal field theories deformed by
one or more relevant operators. The original CFT is described in infinite
volume using a basis of states with definite momentum, $P$, and conformal
Casimir, $\mathcal{C}$. The relevant deformation is then considered using
lightcone quantization, with the resulting Hamiltonian expressed in terms of
this CFT basis. Truncating to states with $\mathcal{C} \leq
\mathcal{C}_{\max}$, one can numerically find the resulting spectrum, as well
as other dynamical quantities, such as spectral densities of operators. This
method requires the introduction of an appropriate regulator, which can be
chosen to preserve the conformal structure of the basis. We check this
framework in three dimensions for various perturbative deformations of a free
scalar CFT, and for the case of a free $O(N)$ CFT deformed by a mass term and a
non-perturbative quartic interaction at large-$N$. In all cases, the truncation
scheme correctly reproduces known analytic results. We also discuss a general
procedure for generating a basis of Casimir eigenstates for a free CFT in any
number of dimensions.Comment: 48+37 pages, 17 figures; v2: references added, small clarification
The 750 GeV Diphoton excess, Dark Matter and Constraints from the
  IceCube experiment

Recent LHC data show hints of a new resonance in the diphoton distribution at
an invariant mass of 750 GeV. Interestingly, this new particle might be both CP
odd and play the role of a portal into the dark matter sector. Under these
assumptions and motivated by the fact that the requirement of $SU(2)_L$
invariance automatically implies the coupling of this alleged new resonance to
$ZZ$ and $Z\gamma$, we investigate the current and future constraints coming
from the indirect searches performed through the neutrino telescope IceCube. We
show that these constraints can be stronger than the ones from direct detection
experiments if the dark matter mass is larger than a few hundred GeV.
Furthermore, in the scenario in which the dark matter is a scalar particle, the
IceCube data limit the cross section between the DM and the proton to values
close to the predicted ones for natural values of the parameters.Comment: 20 pages, 6 figures; v2: added references; v3: published version,
  with some minor edits and including the exclusion bounds from searches of
  gamma ray
On the Validity of the Effective Field Theory Approach to SM Precision
  Tests

We discuss the conditions for an effective field theory (EFT) to give an
adequate low-energy description of an underlying physics beyond the Standard
Model (SM). Starting from the EFT where the SM is extended by dimension-6
operators, experimental data can be used without further assumptions to measure
(or set limits on) the EFT parameters. The interpretation of these results
requires instead a set of broad assumptions (e.g. power counting rules) on the
UV dynamics. This allows one to establish, in a bottom-up approach, the
validity range of the EFT description, and to assess the error associated with
the truncation of the EFT series. We give a practical prescription on how
experimental results could be reported, so that they admit a maximally broad
range of theoretical interpretations. Namely, the experimental constraints on
dimension-6 operators should be reported as functions of the kinematic
variables that set the relevant energy scale of the studied process. This is
especially important for hadron collider experiments where collisions probe a
wide range of energy scales.Comment: 26 pages, 2 figures; v2: Comments and references added, conclusions
  unchange
Interpreting a 750 GeV Diphoton Resonance

We discuss the implications of the significant excesses in the diphoton final
state observed by the LHC experiments ATLAS and CMS around a diphoton invariant
mass of 750 GeV. The interpretation of the excess as a spin-zero s-channel
resonance implies model-independent lower bounds on both its branching ratio
and its coupling to photons, which stringently constrain dynamical models. We
consider both the case where the excess is described by a narrow and a broad
resonance. We also obtain model-independent constraints on the allowed
couplings and branching fractions to final states other than diphotons, by
including the interplay with 8 TeV searches. These results can guide attempts
to construct viable dynamical models of the resonance. Turning to specific
models, our findings suggest that the anomaly cannot be accounted for by the
presence of only an additional singlet or doublet spin-zero field and the
Standard Model degrees of freedom; this includes all two-Higgs-doublet models.
Likewise, heavy scalars in the MSSM cannot explain the excess if stability of
the electroweak vacuum is required, at least in a leading-order analysis. If we
assume that the resonance is broad we find that it is challenging to find a
weakly coupled explanation. However, we provide an existence proof in the form
of a model with vectorlike quarks with large electric charge that is
perturbative up to the 100 TeV scale. For the narrow-resonance case a similar
model can be perturbative up to high scales also with smaller charges. We also
find that, in their simplest form, dilaton models cannot explain the size of
the excess. Some implications for flavor physics are briefly discussed.Comment: 36 pages, 7 figures. v4: added electroweak-boson initial states,
  including with photons; minor improvements of presentation; published versio
Perturbative analysis in higher-spin theories

A new scheme of the perturbative analysis of the nonlinear HS equations is
developed giving directly the final result for the successive application of
the homotopy integrations which appear in the standard approach. It drastically
simplifies the analysis and results from the application of the standard
spectral sequence approach to the higher-spin covariant derivatives, allowing
us in particular to reduce multiple homotopy integrals resulting from the
successive application of the homotopy trick to a single integral. Efficiency
of the proposed method is illustrated by various examples. In particular, it is
shown how the Central on-shell theorem of the free theory immediately results
from the nonlinear HS field equations with no intermediate computations.Comment: 20 pages, V3: typos corrected, references and acknowledgement added,
  normalization of AdS background 1-forms changed; version to appear in JHE
Boundary effects on radiative processes of two entangled atoms

We analyze radiative processes of a quantum system composed by two identical
two-level atoms interacting with a massless scalar field prepared in the vacuum
state in the presence of perfect reflecting flat mirrors. We consider that the
atoms are prepared in a stationary maximally entangled state. We investigate
the spontaneous transitions rates from the entangled states to the collective
ground state induced by vacuum fluctuations. In the empty-space case, the
spontaneous decay rates can be enhanced or inhibited depending on the specific
entangled state and changes with the distance between the atoms. Next, we
consider the presence of perfect mirrors and impose Dirichlet boundary
conditions on such surfaces. In the presence of a single mirror the transition
rate for the symmetric state undergoes a slight reduction, whereas for the
antisymmetric state our results indicate a slightly enhancement. Finally, we
investigate the effect of multiple reflections by two perfect mirrors on the
transition rates.Comment: submitted version to the journa
750 GeV Diphotons: Implications for Supersymmetric Unification II

Perturbative supersymmetric gauge coupling unification is possible in six
theories where complete SU(5) TeV-scale multiplets of vector matter account for
the size of the reported $750~{\rm GeV}$ diphoton resonance, interpreted as a
singlet multiplet $S = (s+ia)/\sqrt{2}$. One of these has a full generation of
vector matter and a unified gauge coupling $\alpha_G \sim 1$. The diphoton
signal rate is enhanced by loops of vector squarks and sleptons, especially
when the trilinear $A$ couplings are large. If the $SH_u H_d$ coupling is
absent, both $s$ and $a$ can contribute to the resonance, which may then have a
large apparent width if the mass splitting from $s$ and $a$ arises from loops
of vector matter. The width depends sensitively on $A$ parameters and phases of
the vector squark and slepton masses. Vector quarks and/or squarks are expected
to be in reach of the LHC. If the $SH_uH_d$ coupling is present, $a$ leads to a
narrow diphoton resonance, while a second resonance with decays $s \rightarrow
hh, W^+ W^-,ZZ$ is likely to be discovered at future LHC runs. In some of the
theories a non-standard origin or running of the soft parameters is required,
for example involving conformal hidden sector interactions.Comment: 26 pages, 11 figure
From strong to weak coupling in holographic models of thermalization

We investigate the analytic structure of thermal energy-momentum tensor
correlators at large but finite coupling in quantum field theories with gravity
duals. We compute corrections to the quasinormal spectra of black branes due to
the presence of higher derivative $R^2$ and $R^4$ terms in the action, focusing
on the dual to $\mathcal{N}=4$ SYM theory and Gauss-Bonnet gravity. We observe
the appearance of new poles in the complex frequency plane at finite coupling.
The new poles interfere with hydrodynamic poles of the correlators leading to
the breakdown of hydrodynamic description at a coupling-dependent critical
value of the wave-vector. The dependence of the critical wave vector on the
coupling implies that the range of validity of the hydrodynamic description
increases monotonically with the coupling. The behavior of the quasinormal
spectrum at large but finite coupling may be contrasted with the known
properties of the hierarchy of relaxation times determined by the spectrum of a
linearized kinetic operator at weak coupling. We find that the ratio of a
transport coefficient such as viscosity to the relaxation time determined by
the fundamental non-hydrodynamic quasinormal frequency changes rapidly in the
vicinity of infinite coupling but flattens out for weaker coupling, suggesting
an extrapolation from strong coupling to the kinetic theory result. We note
that the behavior of the quasinormal spectrum is qualitatively different
depending on whether the ratio of shear viscosity to entropy density is greater
or less than the universal, infinite coupling value of $\hbar/4\pi k_B$. In the
former case, the density of poles increases, indicating a formation of branch
cuts in the weak coupling limit, and the spectral function shows the appearance
of narrow peaks. We also discuss the relation of the viscosity-entropy ratio to
conjectured bounds on relaxation time in quantum systems.Comment: V2: 53 pages, 31 figures. References adde
Explicit Formulae for Yang-Mills-Einstein Amplitudes from the Double
  Copy

Using the double-copy construction of Yang-Mills-Einstein theories formulated
in our earlier work, we obtain compact presentations for single-trace
Yang-Mills-Einstein tree amplitudes with up to five external gravitons and an
arbitrary number of gluons. These are written as linear combinations of
color-ordered Yang-Mills trees, where the coefficients are given by
color/kinematics-satisfying numerators in a Yang-Mills+\phi^3 theory. The
construction outlined in this paper holds in general dimension and extends
straightforwardly to supergravity theories. For one, two, and three external
gravitons, our expressions give identical or simpler presentations of
amplitudes already constructed through string-theory considerations or the
scattering equations formalism. Our results are based on color/kinematics
duality and gauge invariance, and strongly hint at a recursive structure
underlying the single-trace amplitudes with an arbitrary number of gravitons.
For the single-graviton case, we give amplitudes to any loop order and obtain,
through gauge invariance, new loop-level amplitude relations for Yang-Mills
theory.Comment: 36 pages, 3 figures, v2: minor corrections, journal versio
Can we change $c$ in four-dimensional CFTs by exactly marginal
  deformations?

There is no known obstructions, but we have not been aware of any concrete
examples, either. The Wess-Zumino consistency condition for the conformal
anomaly says that $a$ cannot change but does not say anything about $c$. In
supersymmetric models, both $a$ and $c$ are determined from the triangle
t'Hooft anomalies and the unitarity demands that both must be fixed, so the
unitary supersymmetric conformal field theories do not admit such a
possibility. Given this field theory situation, we construct an effective
AdS/CFT model without supersymmetry in which $c$ changes under exactly marginal
deformations. So, yes, we can.Comment: 18 pages, v2: minor corrections, appendix adde
Probing vector-like quark models with Higgs-boson pair production

We investigate Higgs-boson pair production at the LHC when the final state
system arises from decays of vector-like quarks coupling to the Higgs boson and
the Standard Model quarks. Our phenomenological study includes
next-to-leading-order QCD corrections, which are important to guarantee
accurate predictions, and focuses on a detailed analysis of a di-Higgs signal
in the four $b$-jet channel. Whereas existing Run II CMS and ATLAS analyses are
not specifically designed for probing non-resonant, vector-like-quark induced,
di-Higgs production, we show that they nevertheless offer some potential for
these modes. We then investigate the possibility of distinguishing between the
various di-Higgs production mechanisms by exploiting the kinematic properties
of the signal.Comment: 25 pages, 12 figures and 1 table; figure 1 is updated for correct
  bound, references are added, version matches with article published in JHE
Spectrum of the open QCD flux tube and its effective string description
  I: 3d static potential in SU(N=2,3)

We perform a high precision measurement of the static $q\bar{q}$ potential in
three-dimensional SU($N$) gauge theory with $N=2,3$ and compare the results to
the potential obtained from the effective string theory. In particular, we show
that the exponent of the leading order correction in $1/R$ is 4, as predicted,
and obtain accurate results for the continuum limits of the string tension and
the non-universal boundary coefficient $\bar{b}_2$, including an extensive
analysis of all types of systematic uncertainties. We find that the magnitude
of $\bar{b}_2$ decreases with increasing $N$, leading to the possibility of a
vanishing $\bar{b}_2$ in the large $N$ limit. In the standard form of the
effective string theory possible massive modes and the presence of a rigidity
term are usually not considered, even though they might give a contribution to
the energy levels. To investigate the effect of these terms, we perform a
second analysis, including these contributions. We find that the associated
expression for the potential also provides a good description of the data. The
resulting continuum values for $\bar{b}_2$ are about a factor of 2 smaller than
in the standard analysis, due to contaminations from an additional $1/R^4$
term. However, $\bar{b}_2$ shows a similar decrease in magnitude with
increasing $N$. In the course of this extended analysis we also obtain
continuum results for the masses appearing in the additional terms and we find
that they are around twice as large as the square root of the string tension in
the continuum and compatible between SU(2) and SU(3) gauge theory. In the
follow up papers we will extend our investigations to the large $N$ limit and
excited states of the open flux tube.Comment: 40 pages, 10 figures, 11 table
"$1k_F$" Singularities and Finite Density ABJM Theory at Strong Coupling

We study non-analytic behavior in the static charge susceptibility in finite
density states of the ABJM theory using its holographic dual. Emphasis is
placed on a particular state characterized by vanishing entropy density at zero
temperature, and Fermi surface-like singularities in various fermionic
correlation functions. The susceptibility exhibits branch points in the complex
momentum plane, with a real part quantitatively very similar to the location of
the Fermi surface singularities.Comment: 29 pages, 5 figures; v2: Minor additions to overview and discussion,
  some references added, version to appear in JHE
Simulations of Cold Electroweak Baryogenesis: Finding the optimal quench
  time

We revisit the numerical computation of the baryon asymmetry from Cold
Electroweak Baryogenesis given the physical Higgs mass. We investigate the
dependence of the asymmetry on the speed at which electroweak symmetry breaking
takes place. The maximum asymmetry does not occur for arbitrarily fast
quenches, but at quench times of about $\tau_q\simeq 16\, m_H^{-1}$, with no
asymmetry created for quenches slower than $\tau_q>30\, m_H^{-1}$. Curiously,
we also find that the overall sign of the asymmetry depends on the quench time.Comment: 9 pages, 5 figure
A gravitating Yang-Mills instanton

We present an asymptotically flat, spherically symmetric, static, globally
regular and horizonless solution of SU$(2)$-gauged $\mathcal{N}=1,d=5$
supergravity. The SU$(2)$ gauge field is that of the BPST instanton. We argue
that this solution, analogous to the global monopoles found in $d=4$
$\mathcal{N}=2$ and $\mathcal{N}=4$ gauged supergravities, describes the field
of a single string-theory object which does not contribute to the entropy of
black holes when we add it to them and show that it is, indeed, the dimensional
reduction on T$^{5}$ of the gauge 5-brane. We investigate how the energy of the
solution is concentrated as a function of the instanton's scale showing that it
never violates the hoop conjecture although the curvature grows unboundedly in
the zero scale limit.Comment: 19 pages, 4 figures. Some misprints correcte