pinecone/core-2020-05-10-deduplication huggingface dataset:
Higher-spin gravity as a theory on a fixed (anti) de Sitter background

We study Vasiliev's higher-spin gravity in 3+1d. We formulate the theory in
the so-called compensator formalism, where the local isometry group SO(4,1) is
reduced to the Lorentz group SO(3,1) by a choice of spacelike direction in an
internal 4+1d space. We present a consistent extension of Vasiliev's equations
that allows this internal direction to become spacetime-dependent. This allows
a new point of view on the theory, where spacetime is identified with the de
Sitter space of possible internal directions. We thus obtain an interacting
theory of higher-spin massless gauge fields on a fixed, maximally symmetric
background spacetime. We expect implications for the physical interpretation of
higher-spin gravity, for the search for a Lagrangian formulation and/or
quantization, as well as for higher-spin holography.Comment: 17 pages + 3 pages of appendix; v2: generalized to include the full
  interaction ambiguity, added explicit analysis of the equations' consistency;
  v3: standardized normalization conventions between papers; v4: expanded the
  comparison with the standard Vasiliev equations by presenting an intermediate
  formulatio
Simplified models for same-spin new physics scenarios

Simplified models are an important tool for the interpretation of searches
for new physics at the LHC. They are defined by a small number of new particles
together with a specific production and decay pattern. The simplified models
adopted in the experimental analyses thus far have been derived from
supersymmetric theories, and they have been used to set limits on
supersymmetric particle masses. We investigate the applicability of such
simplified supersymmetric models to a wider class of new physics scenarios, in
particular those with same-spin Standard Model partners. We focus on the pair
production of quark partners and analyze searches for jets and missing energy
within a simplified supersymmetric model with scalar quarks and a simplified
model with spin-1/2 quark partners. Despite sizable differences in the
detection efficiencies due to the spin of the new particles, the limits on
particle masses are found to be rather similar. We conclude that the
supersymmetric simplified models employed in current experimental analyses also
provide a reliable tool to constrain same-spin BSM scenarios.Comment: 11 pages + references, 7 figures; v2: added references, minor
  improvements in the presentatio
Wbbj production at NLO with POWHEG+MiNLO

We present a next-to-leading order plus parton-shower event generator for the
production of a W boson plus two bottom quarks and a jet at hadron colliders,
implemented in the POWHEG BOX framework. Bottom-mass effects and spin
correlations of the decay products of the W boson are fully taken into account.
The code has been automatically generated using the two available interfaces to
MadGraph4 and GoSam, the last one updated to a new version. We have applied the
MiNLO prescription to our Wbbj calculation, obtaining a finite differential
cross section also in the limit of vanishing jet transverse momentum.
Furthermore, we have compared several key distributions for Wbbj production
with those generated with a next-to-leading order plus parton-shower event
generator for Wbb production, and studied their factorization- and
renormalization-scale dependence. Finally, we have compared our results with
recent experimental data from the ATLAS and CMS Collaborations.Comment: Version as accepted for publication. Added references, one table and
  one figure. All the rest is the same as version
Equilibration in low-dimensional quantum matrix models

Matrix models play an important role in studies of quantum gravity, being
candidates for a formulation of M-theory, but are notoriously difficult to
solve. In this work, we present a fresh approach by introducing a novel exact
model provably equivalent with low-dimensional bosonic matrix models. In this
equivalent model significant local structure becomes apparent and it can serve
as a simple toy model for analytical and precise numerical study. We derive a
substantial part of the low energy spectrum, find a conserved charge, and are
able to derive numerically the Regge trajectories. To exemplify the usefulness
of the approach, we address questions of equilibration starting from a
non-equilibrium situation, building upon an intuition from quantum information.
We finally discuss possible generalizations of the approach.Comment: 5+2 pages, 2 figures; v2: published versio
Kahler Potential and Ambiguities in 4d N=2 SCFTs

The partition function of four-dimensional N=2 superconformal field theories
on S^4 computes the exact Kahler potential on the space of exactly marginal
couplings [1]. We present a new elementary proof of this result using
supersymmetry Ward identities. The partition function is a section rather than
a function, and is subject to ambiguities coming from Kahler transformations
acting on the Kahler potential. This ambiguity is realized by a local
supergravity counterterm in the underlying SCFT. We provide an explicit
construction of the Kahler ambiguity counterterm in the four dimensional N=2
off-shell supergravity theory that admits S^4 as a supersymmetric background.Comment: 18 pages, LaTeX, corrected counterterm in section
Tinkertoys for the Twisted $E_6$ Theory

We study $4D$ $\mathcal{N}=2$ superconformal field theories that arise as the
compactification of the six-dimensional $(2,0)$ theory of type $E_6$ on a
punctured Riemann surface in the presence of $\mathbb{Z}_2$ outer-automorphism
twists. We explicitly carry out the classification of these theories in terms
of three-punctured spheres and cylinders, and provide tables of properties of
the $\mathbb{Z}_2$-twisted punctures. An expression is given for the
superconformal index of a fixture with twisted punctures of type $E_6$, which
we use to check our identifications. Several of our fixtures have Higgs
branches which are isomorphic to instanton moduli spaces, and we find that
S-dualities involving these fixtures imply interesting isomorphisms between
hyperK\"ahler quotients of these spaces. Additionally, we find families of
fixtures for which the Sommers-Achar group, which was previously a Coulomb
branch concept, acts non-trivially on the Higgs branch operators.Comment: 52 pages, 56 figure
Footprints of Supersymmetry on Higgs Decay

Motivated by future collider proposals that aim to measure the Higgs
properties precisely, we study the partial decay widths of the lightest Higgs
boson in the minimal supersymmetric standard model with an emphasis on the
parameter region where all superparticles and heavy Higgs bosons are not
accessible at the LHC. Taking account of phenomenological constraints such as
the Higgs mass, flavor constraints, vacuum stability, and perturbativity of
coupling constants up to the grand unification scale, we discuss how large the
deviations of the partial decay widths from the standard model predictions can
be. These constraints exclude large fraction of the parameter region where the
Higgs widths show significant deviation from the standard model predictions.
Nevertheless, even if superparticles and the heavy Higgses are out of the reach
of 14TeV LHC, the deviation may be large enough to be observed at future
$e^+e^-$ collider experiments.Comment: 24 pages, 8 figures, version accepted in JHE
Top-quark electroweak couplings at the FCC-ee

An optimal-observable analysis of the lepton angular and energy distributions
from top-quark pair production with semi-leptonic decays in e+e- collisions is
used to predict the potential sensitivity of the FCC-ee to the couplings of the
top quark to the photon and the Z.Comment: 18 pages, 5 figures. To be published in JHEP (accepted for
  publication). Between version 2 and version 3, the suggestions of the JHEP
  referee were implemented both in the text (in Sections "Results and
  discussion" and "Summary and outlook") and in Figures 3 and
The Spectrum in the Sachdev-Ye-Kitaev Model

The SYK model consists of $N\gg 1$ fermions in $0+1$ dimensions with a
random, all-to-all quartic interaction. Recently, Kitaev has found that the SYK
model is maximally chaotic and has proposed it as a model of holography. We
solve the Schwinger-Dyson equation and compute the spectrum of two-particle
states in SYK, finding both a continuous and discrete tower. The four-point
function is expressed as a sum over the spectrum. The sum over the discrete
tower is evaluated.Comment: 29 pages, 2 figure
Positive Signs in Massive Gravity

We derive new constraints on massive gravity from unitarity and analyticity
of scattering amplitudes. Our results apply to a general effective theory
defined by Einstein gravity plus the leading soft diffeomorphism-breaking
corrections. We calculate scattering amplitudes for all combinations of tensor,
vector, and scalar polarizations. The high-energy behavior of these amplitudes
prescribes a specific choice of couplings that ameliorates the ultraviolet
cutoff, in agreement with existing literature. We then derive consistency
conditions from analytic dispersion relations, which dictate positivity of
certain combinations of parameters appearing in the forward scattering
amplitudes. These constraints exclude all but a small island in the parameter
space of ghost-free massive gravity. While the theory of the "Galileon" scalar
mode alone is known to be inconsistent with positivity constraints, this is
remedied in the full massive gravity theory.Comment: 19 pages, 3 figures; supplementary file with full scattering
  amplitude is attached separatel
Top Partners Searches and Composite Higgs Models

Colored fermionic partners of the top quark are well-known signatures of the
Composite Higgs scenario and for this reason they have been and will be subject
of an intensive experimental study at the LHC. Performing an assessment of the
theoretical implications of this experimental effort is the goal of the present
paper. We proceed by analyzing a set of simple benchmark models, characterized
by simple two-dimensional parameter spaces where the results of the searches
are conveniently visualized and their impact quantified. We only draw exclusion
contours, in the hypothesis of no signal, but of course our formalism could
equally well be used to report discoveries in a theoretically useful format.Comment: 32 pages, 15 figure
$\mathcal{N}=2$ central charge bounds from $2d$ chiral algebras

We study protected correlation functions in $\mathcal{N} = 2$ SCFT whose
description is captured by a two-dimensional chiral algebra. Our analysis
implies a new analytic bound for the $c$-anomaly as a function of the flavor
central charge $k$, valid for any theory with a flavor symmetry $G$. Combining
our result with older bounds in the literature puts strong constraints on the
parameter space of $\mathcal{N}=2$ theories. In particular, it singles out a
special set of models whose value of $c$ is uniquely fixed once $k$ is given.
This set includes the canonical rank one $\mathcal{N}=2$ SCFTs given by
Kodaira's classification.Comment: 12 pages, 2 figure
Entropy for gravitational Chern-Simons terms by squashed cone method

In this paper we investigate the entropy of gravitational Chern-Simons terms
for the horizon with non-vanishing extrinsic curvatures, or the holographic
entanglement entropy for arbitrary entangling surface. In 3D we find no anomaly
of entropy appears. But the squashed cone method can not be used directly to
get the correct result. For higher dimensions the anomaly of entropy would
appear, still, we can not use the squashed cone method directly. That is
becasuse the Chern-Simons action is not gauge invariant. To get a reasonable
result we suggest two methods. One is by adding a boundary term to recover the
gauge invariance. This boundary term can be derived from the variation of the
Chern-Simons action. The other one is by using the Chern-Simons relation
$d\bm{\Omega_{4n-1}}=tr(\bm{R}^{2n})$. We notice that the entropy of
$tr(\bm{R}^{2n})$ is a total derivative locally, i.e. $S=d s_{CS}$. We propose
to identify $s_{CS}$ with the entropy of gravitational Chern-Simons terms
$\Omega_{4n-1}$. In the first method we could get the correct result for Wald
entropy in arbitrary dimension. In the second approach, in addition to Wald
entropy, we can also obtain the anomaly of entropy with non-zero extrinsic
curvatures. Our results imply that the entropy of a topological invariant, such
as the Pontryagin term $tr(\bm{R}^{2n})$ and the Euler density, is a
topological invariant on the entangling surface.Comment: 19 pag
Conductivity bounds in probe brane models

We discuss upper and lower bounds on the electrical conductivity of finite
temperature strongly coupled quantum field theories, holographically dual to
probe brane models, within linear response. In a probe limit where disorder is
introduced entirely through an inhomogeneous background charge density, we find
simple lower and upper bounds on the electrical conductivity in arbitrary
dimensions. In field theories in two spatial dimensions, we show that both
bounds persist even when disorder is included in the bulk metric. We discuss
the challenges with finding sharp lower bounds on conductivity in three or more
spatial dimensions when the metric is inhomogeneous.Comment: 16 pages; v2: minor changes, published versio
Symplectically invariant flow equations for N=2, D=4 gauged supergravity
  with hypermultiplets

We consider N=2 supergravity in four dimensions, coupled to an arbitrary
number of vector- and hypermultiplets, where abelian isometries of the
quaternionic hyperscalar target manifold are gauged. Using a static and
spherically or hyperbolically symmetric ansatz for the fields, a
one-dimensional effective action is derived whose variation yields all the
equations of motion. By imposing a sort of Dirac charge quantization condition,
one can express the complete scalar potential in terms of a superpotential and
write the action as a sum of squares. This leads to first-order flow equations,
that imply the second-order equations of motion. The first-order flow turns out
to be driven by Hamilton's characteristic function in the Hamilton-Jacobi
formalism, and contains among other contributions the superpotential of the
scalars. We then include also magnetic gaugings and generalize the flow
equations to a symplectically covariant form. Moreover, by rotating the charges
in an appropriate way, an alternative set of non-BPS first-order equations is
obtained that corresponds to a different squaring of the action. Finally, we
use our results to derive the attractor equations for near-horizon geometries
of extremal black holes.Comment: 27 pages, uses jheppub.sty. v2: Typos corrected, final version to be
  published in JHEP. v3: Prefactor in equ. (3.74) correcte
The Axiverse induced Dark Radiation Problem

The string/$M$ theory Axiverse -- a plethora of very light Axion Like
Particles (ALPs) with a vast range of masses -- is arguably a generic
prediction of string/$M$ theory. String/$M$ theory also tends to predict that
the early Universe is dominated by moduli fields. When the heavy moduli decay,
before nucleosynthesis, they produce dark radiation in the form of relativistic
ALPs. Generically one estimates that the number of relativistic species grows
with the number of axions in the Axiverse, in contradiction to the observations
that $N_{eff} \leq 4$. We explain this problem in detail and suggest some
possible solutions to it. The simplest solution requires that the lightest
modulus decays only into its own axion superpartner plus Standard Model
particles and this severely constrains the moduli Kahler potential and mass
matrix.Comment: 17 pages, 4 figure
Electroweak Baryogenesis with Anomalous Higgs Couplings

We investigate feasibility of efficient baryogenesis at the electroweak scale
within the effective field theory framework based on a non-linear realisation
of the electroweak gauge symmetry. In this framework the LHC Higgs boson is
described by a singlet scalar field, which, therefore, admits new interactions.
Assuming that Higgs couplings with the eletroweak gauge bosons are as in the
Standard Model, we demonstrate that the Higgs cubic coupling and the
CP-violating Higgs-top quark anomalous couplings alone may drive the a strongly
first-order phase transition. The distinguished feature of this transition is
that the anomalous Higgs vacuum expectation value is generally non-zero in both
phases. We identify a range of anomalous couplings, consistent with current
experimental data, where sphaleron rates are sufficiently fast in the
'symmetric' phase and are suppressed in the 'broken' phase and demonstrate that
the desired baryon asymmetry can indeed be generated in this framework. This
range of the Higgs anomalous couplings can be further constrained from the LHC
Run 2 data and be probed at high luminosity LHC and beyond.Comment: 24 pages, 4 figures. V2: references added, version published in JHE
Disorder in Large-N Theories

We consider Euclidean Conformal Field Theories perturbed by quenched
disorder, namely by random fluctuations in their couplings. Such theories are
relevant for second-order phase transitions in the presence of impurities or
other forms of disorder. Theories with quenched disorder often flow to new
fixed points of the renormalization group. We begin with disorder in free field
theories. Imry and Ma showed that disordered free fields can only exist for
d>4. For d>4 we show that disorder leads to new fixed points which are not
scale-invariant. We then move on to large-N theories (vector models or gauge
theories in the `t Hooft limit). We compute exactly the beta function for the
disorder, and the correlation functions of the disordered theory. We generalize
the results of Imry and Ma by showing that such disordered theories exist only
when disorder couples to operators of dimension \Delta > d/4. Sometimes the
disordered fixed points are not scale-invariant, and in other cases they have
unconventional dependence on the disorder, including non-trivial effects due to
irrelevant operators. Holography maps disorder in conformal theories to
stochastic differential equations in a higher-dimensional space. We use this
dictionary to reproduce our field theory results. We also study the leading 1/N
corrections, both by field theory methods and by holography. These corrections
are particularly important when disorder scales with the number of degrees of
freedom.Comment: 40 pages, one figure, harvmac. v2: additional comments about the
  infrared disordered correlation function
Search Strategies for TeV Scale Fermionic Top Partners with Charge 2/3

Searches for fermionic top partners at the TeV scale will bring forward a new
final state kinematic regime and event topologies, where Run I search
strategies will inevitably fail. We propose concrete search strategies for
singly produced charge 2/3 fermionic top partners ($T'$) adequate for LHC Run
II. Our analysis spans over all of the $T'$ decay modes ($i.e.$ $tZ$, $th$ and
$Wb$) where we present detailed discussion of the search performances, signal
efficiencies and backgrounds rates. Our LHC Run II search proposals utilize
signatures with large missing energy and leptons, as well as jet substructure
observables for tagging of boosted heavy SM states, customized $b$-tagging
tactics and forward jet tagging. We analyze the prospects for discovery and
exclusion of $T'$ models within the framework of partially composite quarks at
the LHC Run II. Our results show that the LHC Run II has good prospects for
observing $T'$ models which predict single production cross section of
$\sigma_{T'} \sim 70 -140 \, (30 -65)$ fb for $M_{T'} = 1\, (1.5)$~TeV
respectively with 100 fb$^{-1}$ of integrated luminosity, depending on the
branching ratios of the $T'$. Similarly, we find that cross sections of
$\sigma_{T'} \sim 27 -60\, (13 - 24)$ fb for $M_{T'} = 1\, (1.5)$ TeV
respectively can be excluded with the same amount of data. Our results are
minimally model dependent and can be applied to most $T'$ models where
$\Gamma_{T'} \ll M_{T'}$.Comment: 32 pages, 11 figures, 26 table
Constraining top quark effective theory in the LHC Run II era

We perform an up-to-date global fit of top quark effective theory to
experimental data from the Tevatron, and from LHC Runs I and II. Experimental
data includes total cross-sections up to 13 TeV, as well as differential
distributions, for both single top and pair production. We also include the top
quark width, charge asymmetries, and polarisation information from top decay
products. We present bounds on the coefficients of dimension six operators, and
examine the interplay between inclusive and differential measurements, and
Tevatron / LHC data. All results are currently in good agreement with the
Standard Model.Comment: v1: 23 pages plus references (34 total), 12 figures. v2: Version
  accepted by JHEP. v3: Added table of numerical constraints. v4: Corrected
  typo in table
Sigma Decomposition: The CP-Odd Lagrangian

In Alonso et al., JHEP 12 (2014) 034, the CP-even sector of the effective
chiral Lagrangian for a generic composite Higgs model with a symmetric coset
has been constructed, up to four momenta. In this paper, the CP-odd couplings
are studied within the same context. If only the Standard Model bosonic sources
of custodial symmetry breaking are considered, then at most six independent
operators form a basis. One of them is the weak-$\theta$ term linked to
non-perturbative sources of CP viola- tion, while the others describe CP-odd
perturbative couplings between the Standard Model gauge bosons and an
Higgs-like scalar belonging to the Goldstone boson sector. The procedure is
then applied to three distinct exemplifying frameworks: the original
$SU(5)/SO(5)$ Georgi-Kaplan model, the minimal custodial-preserving
$SO(5)/SO(4)$ model and the minimal $SU(3)/(SU(2)\times U(1))$ model, which
intrinsically breaks cus- todial symmetry. Moreover, the projection of the
high-energy electroweak effective theory to the low-energy chiral effective
Lagrangian for a dynamical Higgs is per- formed, uncovering strong relations
between the operator coefficients and pinpointing the differences with the
elementary Higgs scenario.Comment: 20 pages. V2: new table II added; version published on JHEP. arXiv
  admin note: text overlap with arXiv:1409.158
On Axionic Field Ranges, Loopholes and the Weak Gravity Conjecture

In this short note we clarify some aspects of the impact that the Weak
Gravity Conjecture has on models of (generalized) natural inflation. We address
in particular certain technical and conceptual concerns recently raised
regarding the stringent constraints and conclusions found in our previous work
(arXiv:1503.04783). We also point out the difficulties faced by attempts to
evade these constraints. These new considerations improve the understanding of
the quantum gravity constraints we found and further support the conclusion
that it remains challenging for axions to drive natural inflation.Comment: 14 page