pinecone/core-2020-05-10-deduplication huggingface dataset:
Universality of Sparse $d>2$ Conformal Field Theory at Large $N$

We derive necessary and sufficient conditions for large $N$ conformal field
theories to have a universal free energy and an extended range of validity of
the higher-dimensional Cardy formula. These constraints are much tighter than
in two dimensions and must be satisfied by any conformal field theory dual to
Einstein gravity. We construct and analyze symmetric product orbifold theories
on $\mathbb{T}^d$ and show that they only realize the necessary phase structure
and extended range of validity if the seed theory is assumed to have a
universal vacuum energy.Comment: 32 pages + appendice
Tensor Galileons and Gravity

The particular structure of Galileon interactions allows for
higher-derivative terms while retaining second order field equations for scalar
fields and Abelian $p$-forms. In this work we introduce an index-free
formulation of these interactions in terms of two sets of Grassmannian
variables. We employ this to construct Galileon interactions for mixed-symmetry
tensor fields and coupled systems thereof. We argue that these tensors are the
natural generalization of scalars with Galileon symmetry, similar to $p$-forms
and scalars with a shift-symmetry. The simplest case corresponds to linearised
gravity with Lovelock invariants, relating the Galileon symmetry to
diffeomorphisms. Finally, we examine the coupling of a mixed-symmetry tensor to
gravity, and demonstrate in an explicit example that the inclusion of
appropriate counterterms retains second order field equations.Comment: 24 pages; v2: references added, minor clarification
Fundamental Flavours, Fields and Fixed Points: A Brief Account

In this article we report on a preliminary study, {\it via} Holography, of
infrared fixed points in a putative strongly coupled SU$(N_c)$ gauge theory,
with $N_f$ fundamental matter, in the presence of additional fields in the
fundamental sector, e.g. density or a magnetic field. In an inherently {\it
effective} or a {\it bottom up} approach, we work with a simple system:
Einstein-gravity with a negative cosmological constant, coupled to a
Dirac-Born-Infeld (DBI) matter. We obtain a class of exact solutions, dual to
candidate grounds states in the infrared (IR), with a scaling ansatz for
various fields. These solutions are of two kinds: AdS$_m \times {\mathbb
R}^n$--type, and AdS$_m \times$EAdS$_n$--type, where $m$ and $n$ are suitable
integers. Both these classes of solutions are {\it non-perturbative} in
back-reaction. The AdS$_m \times$EAdS$_n$--type contains examples of Bianchi
type-V solutions. We also construct explicit numerical flows from an AdS$_5$
ultraviolet to both an AdS$_2$ and an AdS$_3$ IR.Comment: 32 pages, 6 figures, references added, published versio
Dark Matter and the Higgs in Natural SUSY

Null results from dark matter (DM) direct detection experiments and the 125
GeV Higgs both pose serious challenges to minimal supersymmetry. In this paper,
we propose a simple extension of the MSSM that economically solves both
problems: a "dark sector" consisting of a singlet and a pair of $SU(2)$
doublets. Loops of the dark sector fields help lift the Higgs mass to 125 GeV
consistent with naturalness, while the lightest fermion in the dark sector can
be viable thermal relic DM, provided that it is mostly singlet. The DM relic
abundance is controlled by s-wave annihilation to tops and Higgsinos, leading
to a tight relation between the relic abundance and the spin-dependent direct
detection cross section. As a result, the model will be fully probed by the
next generation of direct detection experiments. Finally we discuss the
discovery potential at LHC Run II.Comment: 37 pages, 15 figures, updated LUX limit
Supersymmetric partition functions and the three-dimensional A-twist

We study three-dimensional $\mathcal{N}=2$ supersymmetric gauge theories on
$\mathcal{M}_{g,p}$, an oriented circle bundle of degree $p$ over a closed
Riemann surface, $\Sigma_g$. We compute the $\mathcal{M}_{g,p}$ supersymmetric
partition function and correlation functions of supersymmetric loop operators.
This uncovers interesting relations between observables on manifolds of
different topologies. In particular, the familiar supersymmetric partition
function on the round $S^3$ can be understood as the expectation value of a
so-called "fibering operator" on $S^2 \times S^1$ with a topological twist.
More generally, we show that the 3d $\mathcal{N}=2$ supersymmetric partition
functions (and supersymmetric Wilson loop correlation functions) on
$\mathcal{M}_{g,p}$ are fully determined by the two-dimensional A-twisted
topological field theory obtained by compactifying the 3d theory on a circle.
We give two complementary derivations of the result. We also discuss
applications to F-maximization and to three-dimensional supersymmetric
dualities.Comment: 84 pages plus appendix, 8 figures; v2: added reference
Phenomenological study of extended seesaw model for light sterile
  neutrino

We study the zero textures of the Yukawa matrices in the minimal extended
type-I seesaw (MES) model which can give rise to $\sim$ eV scale sterile
neutrinos. In this model, three right handed neutrinos and one extra singlet
$S$ are added to generate a light sterile neutrino. The light neutrino mass
matrix for the active neutrinos, $ m_{\nu}$, depends on the Dirac neutrino mass
matrix ($ M_{D} $), Majorana neutrino mass matrix ($ M_{R} $) and the mass
matrix ($ M_{S} $) coupling the right handed neutrinos and the singlet. The
model predicts one of the light neutrino masses to vanish. We systematically
investigate the zero textures in $ M_{D} $ and observe that maximum five zeros
in $ M_{D} $ can lead to viable zero textures in $ m_{\nu} $. For this study we
consider four different forms for $ M_R $ (one diagonal and three off diagonal)
and two different forms of $(M_{S})$ containing one zero. Remarkably we obtain
only two allowed forms of $ m_{\nu} $ ($m_{e\tau} = 0 $ and $m_{\tau\tau}=0$)
having inverted hierarchical mass spectrum. We re-analyze the phenomenological
implications of these two allowed textures of $m_\nu$ in the light of recent
neutrino oscillation data. In the context of the MES model, we also express the
low energy mass matrix, the mass of the sterile neutrino and the active-sterile
mixing in terms of the parameters of the allowed Yukawa matrices. The MES model
leads to some extra correlations which disallow some of the Yukawa textures
obtained earlier, even though they give allowed one-zero forms of $m_\nu$. We
show that the allowed textures in our study can be realized in a simple way in
a model based on MES mechanism with a discrete Abelian flavor symmetry group
$Z_8 \times Z_2$.Comment: 29 pages, 6 figures and 7 tables, Version accepted for publication in
  JHE
Atiyah-Manton Construction of Skyrmions in Eight Dimensions

We show that the eight-dimensional instanton solution, which satisfies the
self-duality equation $F \wedge F = *_8 F \wedge F$, realizes the static
Skyrmion configuration in eight dimensions through the Atiyah-Manton
construction. The relevant energy functional of the Skyrme field is obtained by
the formalism developed by Sutcliffe. By comparing the Skyrmion olution
associated with the extreme of the energy, with the Atiyah-Manton solution
constructed by the instantons, we find that they agree with high accuracy. This
is a higher-dimensional analogue of the Atiyah-Manton construction of Skyrmions
in four dimensions. Our result indicates that the instanton/Skyrmion
correspondence seems to be an universal property in $4k \ (k=1, 2, \ldots)$
dimensions.Comment: 23 pages, 5 figures, published versio
Real topological string amplitudes

We discuss the physical superstring correlation functions in type I theory
(or equivalently type II with orientifold) that compute real topological string
amplitudes. We consider the correlator corresponding to holomorphic derivative
of the real topological amplitude $G_\chi$, at fixed worldsheet Euler
characteristic $\chi$. This corresponds in the low-energy effective action to
N=2 Weyl multiplet, appropriately reduced to the orientifold invariant part,
and raised to the power $g'=-\chi+1$. We show that the physical string
correlator gives precisely the holomorphic derivative of topological amplitude.
Finally, we apply this method to the standard closed oriented case as well, and
prove a similar statement for the topological amplitude $F_g$
Origin of Soft Limits from Nonlinear Supersymmetry in Volkov-Akulov
  Theory

We apply the background field technique, recently developed for a general
class of nonlinear symmetries, at tree level, to the Volkov-Akulov theory with
spontaneously broken N=1 supersymmetry. We find that the background field
expansion in terms of the free fields to the lowest order reproduces the
nonlinear supersymmetry transformation rules. The double soft limit of the
background field is, in agreement with the new general identities, defined by
the algebra of the nonlinear symmetries.Comment: 10
Chiral vortical effect from the compactified D4-branes with smeared
  D0-brane charge

By using the boundary derivative expansion formalism of fluid/gravity
correspondence, we study the chiral vortical effect from the compactified
D4-branes with smeared D0-brane charge. This background corresponds to a
strongly coupled, nonconformal relativistic fluid with a conserved vector
current. The presence of the chiral vortical effect is induced by the addition
of a Chern-Simons term in the bulk action. Except that the non-dissipative
anomalous viscous coefficient and the sound speed rely only on the chemical
potential, most of the other thermal and hydrodynamical quantities of the first
order depend both on the temperature and the chemical potential. According to
our result, the way that the chiral vortical effect coefficient depends on the
chemical potential seems irrelevant with whether the relativistic fluid is
conformal or not. Stability analysis shows that this anomalous relativistic
fluid is stable and the doping of the smeared D0-brane charge will slow down
the sound speed.Comment: 30 pages, 1 tabl
A new class of integrable deformations of CFTs

We construct a new class of integrable $\sigma$-models based on current
algebra theories for a general semisimple group $G$ by utilizing a left-right
asymmetric gauging. Their action can be thought of as the all-loop effective
action of two independent WZW models for $G$ both at level $k$, perturbed by
current bilinears mixing the different WZW models. A non-perturbative symmetry
in the couplings parametric space is revealed. We perform the Hamiltonian
analysis of the action and demonstrate integrability in several cases. We
extend our construction to deformations of $G/H$ CFTs and show integrability
when $G/H$ is a symmetric space. Our method resembles that used for
constructing the $\lambda$-deformed integrable $\sigma$-models, but the results
are distinct and novel.Comment: 25 pages, minor typos corrected, published versio
Holographic Entanglement Entropy for Gravitational Anomaly in Four
  Dimensions

We compute the holographic entanglement entropy for the anomaly polynomial
$\mathrm{Tr} R^2$ in 3+1 dimensions. Using the perturbative method developed
for computing entanglement entropy for quantum field theories, we also compute
the parity odd contribution to the entanglement entropy of the dual field
theory that comes from a background gravitational Chern-Simons term. We find
that, in leading order in the perturbation of the background geometry, the two
contributions match except for a logarithmic divergent term on the field theory
side. We interpret this extra contribution as encoding our ignorance of the
source which creates the perturbation of the geometry.Comment: 14 pages. References update
Harmony of Spinning Conformal Blocks

Conformal blocks for correlation functions of tensor operators play an
increasingly important role for the conformal bootstrap programme. We develop a
universal approach to such spinning blocks through the harmonic analysis of
certain bundles over a coset of the conformal group. The resulting Casimir
equations are given by a matrix version of the Calogero-Sutherland Hamiltonian
that describes the scattering of interacting spinning particles in a
1-dimensional external potential. The approach is illustrated in several
examples including fermionic seed blocks in 3D CFT where they take a very
simple form.Comment: 24 pages, v2: typos corrected, minor change
The Lightcone Bootstrap and the Spectrum of the 3d Ising CFT

We compute numerically the dimensions and OPE coefficients of several
operators in the 3d Ising CFT, and then try to reverse-engineer the solution to
crossing symmetry analytically. Our key tool is a set of new techniques for
computing infinite sums of SL(2,R) conformal blocks. Using these techniques, we
solve the lightcone bootstrap to all orders in an asymptotic expansion in large
spin, and suggest a strategy for going beyond the large spin limit. We carry
out the first steps of this strategy for the 3d Ising CFT, deriving analytic
approximations for the dimensions and OPE coefficients of several infinite
families of operators in terms of the initial data
$\{\Delta_\sigma,\Delta_\epsilon,f_{\sigma\sigma\epsilon},f_{\epsilon\epsilon\epsilon},c_T\}$.
The analytic results agree with numerics to high precision for about 100
low-twist operators (correctly accounting for O(1) mixing effects between
large-spin families). Plugging these results back into the crossing equations,
we obtain approximate analytic constraints on the initial data.Comment: 65+25 pages, 21 figure
Lie n-algebras of BPS charges

We uncover higher algebraic structures on Noether currents and BPS charges.
It is known that equivalence classes of conserved currents form a Lie algebra.
We show that at least for target space symmetries of higher parameterized
WZW-type sigma-models this naturally lifts to a Lie (p+1)-algebra structure on
the Noether currents themselves. Applied to the Green-Schwarz-type action
functionals for super p-brane sigma-models this yields super Lie (p+1)-algebra
refinements of the traditional BPS brane charge extensions of supersymmetry
algebras. We discuss this in the generality of higher differential geometry,
where it applies also to branes with (higher) gauge fields on their
worldvolume. Applied to the M5-brane sigma-model we recover and properly
globalize the M-theory super Lie algebra extension of 11-dimensional
superisometries by 2-brane and 5-brane charges. Passing beyond the
infinitesimal Lie theory we find cohomological corrections to these charges in
higher analogy to the familiar corrections for D-brane charges as they are
lifted from ordinary cohomology to twisted K-theory. This supports the proposal
that M-brane charges live in a twisted cohomology theory.Comment: 19 pages, v2: references added, details of the main computation
  spelled ou
Lifshitz Anomalies, Ward Identities and Split Dimensional Regularization

We analyze the structure of the stress-energy tensor correlation functions in
Lifshitz field theories and construct the corresponding anomalous Ward
identities. We develop a framework for calculating the anomaly coefficients
that employs a split dimensional regularization and the pole residues. We
demonstrate the procedure by calculating the free scalar Lifshitz scale
anomalies in $2+1$ spacetime dimensions. We find that the analysis of the
regularization dependent trivial terms requires a curved spacetime description
without a foliation structure. We discuss potential ambiguities in Lifshitz
scale anomaly definitions.Comment: 68 pages, 3 figures; Added some clarifications, references and
  acknowledgment
Relative entropy and the RG flow

We consider the relative entropy between vacuum states of two different
theories: a conformal field theory (CFT), and the CFT perturbed by a relevant
operator. By restricting both states to the null Cauchy surface in the causal
domain of a sphere, we make the relative entropy equal to the difference of
entanglement entropies. As a result, this difference has the positivity and
monotonicity properties of relative entropy. From this it follows a simple
alternative proof of the c-theorem in d=2 space-time dimensions and, for d>2,
the proof that the coefficient of the area term in the entanglement entropy
decreases along the renormalization group (RG) flow between fixed points. We
comment on the regimes of convergence of relative entropy, depending on the
space-time dimensions and the conformal dimension $\Delta$ of the perturbation
that triggers the RG flow.Comment: 27 pages, 2 figure
A defect in holographic interpretations of tensor networks

We initiate the study of how tensor networks reproduce properties of static
holographic space-times, which are not locally pure anti-de Sitter. We consider
geometries that are holographically dual to ground states of defect, interface
and boundary CFTs and compare them to the structure of the requisite MERA
networks predicted by the theory of minimal updates. When the CFT is deformed,
certain tensors require updating. On the other hand, even identical tensors can
contribute differently to estimates of entanglement entropies. We interpret
these facts holographically by associating tensor updates to turning on
non-normalizable modes in the bulk. In passing, we also clarify and complement
existing arguments in support of the theory of minimal updates, propose a novel
ansatz called rayed MERA that applies to a class of generalized interface CFTs,
and analyze the kinematic spaces of the thin wall and AdS3-Janus geometries.Comment: v2: changed to match published versio
Leptonic mono-top from single stop production at LHC

Top squark (stop) can be produced via QCD interaction but also the
electroweak interaction at the LHC. In this paper, we investigate the
observability of the associated production of stop and chargino, $pp \to
\tilde{t}_1\tilde{\chi}^-_1$, in compressed electroweakino scenario at the 14
TeV LHC. Due to the small mass-splitting between the lightest neutralino
($\tilde{\chi}^0_1$) and chargino ($\tilde{\chi}^-_1$), such a single stop
production can give a mono-top signature through the stop decay $\tilde{t}_1
\to t \tilde{\chi}^0_1$. Focusing on the leptonic mono-top channel, we propose
a lab-frame observable $\cos\theta_{b\ell}$ to reduce the SM backgrounds in
virtue of a boosted top quark from the stop decay. We find that the single stop
production can be probed at $2\sigma$ level at the HL-LHC for
$m_{\tilde{t}_1}<760$ GeV and $m_{\tilde{\chi}^0_1}<150$ GeV.Comment: 15 pages, discussions added, version accepted by JHE
CHY Loop Integrands from Holomorphic Forms

Recently, the Cachazo-He-Yuan (CHY) approach for calculating scattering
amplitudes has been extended beyond tree level. In this paper, we introduce a
way of constructing CHY integrands for $\Phi^3$ theory up to two loops from
holomorphic forms on Riemann surfaces. We give simple rules for translating
Feynman diagrams into the corresponding CHY integrands. As a complementary
result, we extend the $\Lambda$-algorithm, originally introduced in
arXiv:1604.05373, to two loops. Using this approach, we are able to
analytically verify our prescription for the CHY integrands up to seven
external particles at two loops. In addition, it gives a natural way of
extending to higher-loop orders.Comment: 30+12 pages, notation modified and references adde
Connected formulas for amplitudes in standard model

Witten's twistor string theory has led to new representations of S-matrix in
massless QFT as a single object, including Cachazo-He-Yuan formulas in general
and connected formulas in four dimensions. As a first step towards more
realistic processes of the standard model, we extend the construction to QCD
tree amplitudes with massless quarks and those with a Higgs boson. For both
cases, we find connected formulas in four dimensions for all multiplicities
which are very similar to the one for Yang-Mills amplitudes. The formula for
quark-gluon color-ordered amplitudes differs from the pure-gluon case only by a
Jacobian factor that depends on flavors and orderings of the quarks. In the
formula for Higgs plus multi-parton amplitudes, the massive Higgs boson is
effectively described by two additional massless legs which do not appear in
the Parke-Taylor factor. The latter also represents the first
twistor-string/connected formula for form factors.Comment: 18 pages, 3 figure
The N2HDM under Theoretical and Experimental Scrutiny

The N2HDM is based on the CP-conserving 2HDM extended by a real scalar
singlet field. Its enlarged parameter space and its fewer symmetry conditions
as compared to supersymmetric models allow for an interesting phenomenology
compatible with current experimental constraints, while adding to the 2HDM
sector the possibility of Higgs-to-Higgs decays with three different Higgs
bosons. In this paper the N2HDM is subjected to detailed scrutiny. Regarding
the theoretical constraints we implement tests of tree-level perturbativity and
vacuum stability. Moreover, we present, for the first time, a thorough analysis
of the global minimum of the N2HDM. The model and the theoretical constraints
have been implemented in ScannerS, and we provide N2HDECAY, a code based on
HDECAY, for the computation of the N2HDM branching ratios and total widths
including the state-of-the-art higher order QCD corrections and off-shell
decays. We then perform an extensive parameter scan in the N2HDM parameter
space, with all theoretical and experimental constraints applied, and analyse
its allowed regions. We find that large singlet admixtures are still compatible
with the Higgs data and investigate which observables will allow to restrict
the singlet nature most effectively in the next runs of the LHC. Similarly to
the 2HDM, the N2HDM exhibits a wrong-sign parameter regime, which will be
constrained by future Higgs precision measurements.Comment: 36 pages, 11 figures, 6 tables. The N2HDECAY code and documentation
  can be found at https://www.itp.kit.edu/~maggie/N2HDECAY/ . The N2HDM scan
  model implementation in ScannerS can be found at
  http://scanners.hepforge.org/ . Added absolute value in eq. (3.47) and
  corrected braces in eqs. (C.23) and (C.25
Localization of supersymmetric field theories on non-compact hyperbolic
  three-manifolds

We study supersymmetric gauge theories with an R-symmetry, defined on
non-compact, hyperbolic, Riemannian three-manifolds, focusing on the case of a
supersymmetry-preserving quotient of Euclidean AdS$_3$. We compute the exact
partition function in these theories, using the method of localization, thus
reducing the problem to the computation of one-loop determinants around a
supersymmetric locus. We evaluate the one-loop determinants employing three
different techniques: an index theorem, the method of pairing of eigenvalues,
and the heat kernel method. Along the way, we discuss aspects of supersymmetry
in manifolds with a conformal boundary, including supersymmetric actions and
boundary conditions.Comment: v3:79p, minor clarifications and references adde
Coherent Neutrino-Nucleus Scattering and new Neutrino Interactions

We investigate the potential to probe new neutrino physics with future
experiments measuring coherent neutrino-nucleus scattering. Experiments with
high statistics should become feasible soon and allow to constrain parameters
with unprecedented precision. Using a benchmark setup for a future experiment
probing reactor neutrinos, we study the sensitivity on neutrino non-standard
interactions and new exotic neutral currents (scalar, tensor, etc). Compared to
Fermi interaction, percent and permille level strengths of the new interactions
can be probed, superseding for some observables the limits from future neutrino
oscillation experiments by up to two orders of magnitude.Comment: 21 pages, 12 figures, comments added, version to appear in JHE