pinecone/core-2020-05-10-deduplication huggingface dataset:
Holographic bulk viscosity: GPR vs EO

Recently Eling and Oz (EO) proposed a formula for the holographic bulk
viscosity, in arXiv:1103.1657, derived from the null horizon focusing equation.
This formula seems different from that obtained earlier by Gubser, Pufu and
Rocha (GPR) in arXiv:0806.0407 calculated from the IR limit of the two-point
function of the trace of the stress tensor. The two were shown to agree only
for some simple scaling cases. We point out that the two formulae agree in two
non-trivial holographic theories describing RG flows. The first is the strongly
coupled N=2* gauge theory plasma. The second is the semi-phenomenological model
of Improved Holographic QCD.Comment: 21 pages, 2 figure
Distinguishing spins at the LHC using bound state signals

A pair of new colored particles produced near the threshold can form a bound
state and then annihilate into standard model particles. In this paper we show
how the bound state signals can distinguish between two scenarios that have
similar particle content and interactions but different spins, such as the
minimal supersymmetric standard model (MSSM) and universal extra dimensions
(UED). We find, for example, that bound states of KK gluons (KK gluonia) have
an order of magnitude larger cross sections than gluinonia and they may be
detectable as resonances in the $b\bar b$, $t\bar t$ or $\gamma\gamma$ channels
if the KK gluon is very light and sufficiently long-lived. KK gluonia can be
distinguished from gluinonia by their much larger cross sections and distinct
angular distributions. Similarly, KK quarkonia can be distinguished from
squarkonia by the size of their diphoton cross section and by their dilepton
signals. Since many of our results are largely determined by gauge
interactions, they will be useful for many other new physics scenarios as well.Comment: 42 pages, 20 figures; v2: added minor clarifications and references;
  published versio
D=3, N=8 conformal supergravity and the Dragon window

We give a superspace description of D=3, N=8 supergravity. The formulation is
off-shell in the sense that the equations of motion are not implied by the
superspace constraints (but an action principle is not given). The multiplet
structure is unconventional, which we connect to the existence of a "Dragon
window", that is modules occurring in the supercurvature but not in the
supertorsion. According to Dragon's theorem this cannot happen above three
dimensions. We clarify the relevance of this window for going on the conformal
shell, and discuss some aspects of coupling to conformal matter.Comment: plain tex, 24 pp v2: minor change
Yang-Mills instantons on cones and sine-cones over nearly Kahler manifolds

We present a unified eight-dimensional approach to instanton equations on several seven-dimensional manifolds associated to a six-dimensional homogeneous nearly Kahler manifold. The cone over the sine-cone on a nearly Kahler manifold has holonomy group Spin(7) and can be foliated by submanifolds with either holonomy group G(2), a nearly parallel G(2)-structure or a cocalibrated G(2)-structure. We show that there is a G(2)-instanton on each of these seven-dimensional manifolds which gives rise to a Spin(7)-instanton in eight dimensions. The well-known octonionic instantons on R-7 and R-8 are contained in our construction as the special cases of an instanton on the cone and on the cone over the sine-cone, both over the six-sphere, respectively
Aspects of ABJM orbifolds with discrete torsion

We analyze orbifolds with discrete torsion of the ABJM theory by a finite
subgroup $\Gamma$ of $SU(2)\times SU(2)$ . Discrete torsion is implemented by
twisting the crossed product algebra resulting after orbifolding. It is shown
that, in general, the order $m$ of the cocycle we chose to twist the algebra by
enters in a non trivial way in the moduli space. To be precise, the M-theory
fiber is multiplied by a factor of $m$ in addition to the other effects that
were found before in the literature. Therefore we got a
$\mathbb{Z}_{\frac{k|\Gamma|}{m}}$ action on the fiber. We present a general
analysis on how this quotient arises along with a detailed analysis of the
cases where $\Gamma$ is abelian
From correlation functions to Wilson loops

We start with an n-point correlation function in a conformal gauge theory. We
show that a special limit produces a polygonal Wilson loop with $n$ sides. The
limit takes the $n$ points towards the vertices of a null polygonal Wilson loop
such that successive distances $x^2_{i,i+1} \to 0$. This produces a fast moving
particle that generates a "frame" for the Wilson loop. We explain in detail how
the limit is approached, including some subtle effects from the propagation of
a fast moving particle in the full interacting theory. We perform perturbative
checks by doing explicit computations in N=4 super-Yang-Mills.Comment: 37 pages, 10 figures; typos corrected, references adde
Relation between the 4d superconformal index and the S^3 partition
  function

A relation between the 4d superconformal index and the S^3 partition function
is studied with focus on the 4d and 3d actions used in localization. In the
case of vanishing Chern-Simons levels and round S^3 we explicitly show that the
3d action is obtained from the 4d action by dimensional reduction up to terms
which do not affect the exact results. By combining this fact and a recent
proposal concerning a squashing of S^3 and SU(2) Wilson line, we obtain a
formula which gives the partition function depending on the Weyl weight of
chiral multiplets, real mass parameters, FI parameters, and a squashing
parameter as a limit of the index of a parent 4d theory.Comment: 20 pages, LaTeX; v2: comments added; v3: minor corrections, version
  published in JHE
Effective AdS/renormalized CFT

For an effective AdS theory, we present a simple prescription to compute the
renormalization of its dual boundary field theory. In particular, we define
anomalous dimension holographically as the dependence of the wave-function
renormalization factor on the radial cutoff in the Poincare patch of AdS. With
this definition, the anomalous dimensions of both single- and double- trace
operators are calculated. Three different dualities are considered with the
field theory being CFT, CFT with a double-trace deformation and spontaneously
broken CFT. For the second dual pair, we compute scaling corrections at the UV
and IR fixed points of the RG flow triggered by the double-trace deformation.
For the last case, we discuss whether our prescription is sensitive to the AdS
interior or equivalently, the IR physics of the dual field theory.Comment: 20 pages, 3 figure
Polynomials, Riemann surfaces, and reconstructing missing-energy events

We consider the problem of reconstructing energies, momenta, and masses in
collider events with missing energy, along with the complications introduced by
combinatorial ambiguities and measurement errors. Typically, one reconstructs
more than one value and we show how the wrong values may be correlated with the
right ones. The problem has a natural formulation in terms of the theory of
Riemann surfaces. We discuss examples including top quark decays in the
Standard Model (relevant for top quark mass measurements and tests of spin
correlation), cascade decays in models of new physics containing dark matter
candidates, decays of third-generation leptoquarks in composite models of
electroweak symmetry breaking, and Higgs boson decay into two tau leptons.Comment: 28 pages, 6 figures; version accepted for publication, with
  discussion of Higgs to tau tau deca
What two models may teach us about duality violations in QCD

Though the operator product expansion is applicable in the calculation of
current correlation functions in the Euclidean region, when approaching the
Minkowskian domain, violations of quark-hadron duality are expected to occur,
due to the presence of bound-state or resonance poles. In QCD finite-energy sum
rules, contour integrals in the complex energy plane down to the Minkowskian
axis have to be performed, and thus the question arises what the impact of
duality violations may be. The structure and possible relevance of duality
violations is investigated on the basis of two models: the Coulomb system and a
model for light-quark correlators which has already been studied previously. As
might yet be naively expected, duality violations are in some sense "maximal"
for zero-width bound states and they become weaker for broader resonances whose
poles lie further away from the physical axis. Furthermore, to a certain
extent, they can be suppressed by choosing appropriate weight functions in the
finite-energy sum rules. A simplified Ansatz for including effects of duality
violations in phenomenological QCD sum rule analyses is discussed as well.Comment: 17 pages, 6 figures; version to appear in JHE
Lepton Flavor Violation and non-unitarity Lepton Mixing in Low-Scale Type-I Seesaw

Within low-scale seesaw mechanisms, such as the inverse and linear seesaw, one expects (i) potentially large lepton flavor violation (LFV) and (ii) sizeable non-standard neutrino interactions (NSI). We consider the interplay between the magnitude of non-unitarity effects in the lepton mixing matrix, and the constraints that follow from LFV searches in the laboratory. We find that NSI parameters can be sizeable, up to percent level in some cases, while LFV rates, such as that for \mu -> e \gamma, lie within current limits, including the recent one set by the MEG collaboration. As a result the upcoming long baseline neutrino experiments offer a window of opportunity for complementary LFV and weak universality tests
Black holes and black strings of N=2, d=5 supergravity in the H-FGK
  formalism

We study general classes and properties of extremal and non-extremal static
black-hole solutions of N=2, d=5 supergravity coupled to vector multiplets
using the recently proposed H-FGK formalism, which we also extend to static
black strings. We explain how to determine the integration constants and
physical parameters of the black-hole and black-string solutions. We derive
some model-independent statements, including the transformation of non-extremal
flow equations to the form of those for the extremal flow. We apply our methods
to the construction of example solutions (among others a new extremal string
solution of heterotic string theory on K_3 \times S^1). In the cases where we
have calculated it explicitly, the product of areas of the inner and outer
horizon of a non-extremal solution coincides with the square of the
moduli-independent area of the horizon of the extremal solution with the same
charges.Comment: 33 pages. Revised version: references added. No other change
Massive Gravity Theories and limits of Ghost-free Bigravity models

We construct a class of theories which extend New Massive Gravity to higher
orders in curvature in any dimension. The lagrangians arise as limits of a new
class of bimetric theories of Lovelock gravity, which are unitary theories free
from the Boulware-Deser ghost. These Lovelock bigravity models represent the
most general non-chiral ghost-free theories of an interacting massless and
massive spin-two field in any dimension. The scaling limit is taken in such a
way that unitarity is explicitly broken, but the Boulware-Deser ghost remains
absent. This automatically implies the existence of a holographic $c$-theorem
for these theories. We also show that the Born-Infeld extension of New Massive
Gravity falls into our class of models demonstrating that this theory is also
free of the Boulware-Deser ghost. These results extend existing connections
between New Massive Gravity, bigravity theories, Galileon theories and
holographic $c$-theorems.Comment: 11+5 page
Generalized Attractors in Five-Dimensional Gauged Supergravity

In this paper we study generalized attractors in N=2 gauged supergravity
theory in five dimensions coupled to arbitrary number of hyper, vector and
tensor multiplets. We look for attractor solutions with constant anholonomy
coefficients. By analyzing the equations of motion we derive the attractor
potential. We further show that the generalized attractor potential can be
obtained from the fermionic shifts. We study some simple examples and show that
constant anholonomy gives rise to homogeneous black branes in five dimensions.Comment: 30 pages, no figures,V3 minor revisions, to appear in JHE
Non-conformal Hydrodynamics in Einstein-dilaton Theory

In the Einestein-dilaton theory with a Liouville potential parameterized by
$\eta$, we find a Schwarzschild-type black hole solution. This black hole
solution, whose asymptotic geometry is described by the warped metric, is
thermodynamically stable only for $0 \le \eta < 2$. Applying the gauge/gravity
duality, we find that the dual gauge theory represents a non-conformal thermal
system with the equation of state depending on $\eta$. After turning on the
bulk vector fluctuations with and without a dilaton coupling, we calculate the
charge diffusion constant, which indicates that the life time of the quasi
normal mode decreases with $\eta$. Interestingly, the vector fluctuation with
the dilaton coupling shows that the DC conductivity increases with temperature,
a feature commonly found in electrolytes.Comment: 27 pages and 2 figures, published in JHE
An expansion for Neutrino Phenomenology

We develop a formalism for constructing the Pontecorvo-Maki-Nakagawa-Sakata
(PMNS) matrix and neutrino masses using an expansion that originates when a
sequence of heavy right handed neutrinos are integrated out, assuming a seesaw
mechanism for the origin of neutrino masses. The expansion establishes
relationships between the structure of the PMNS matrix and the mass differences
of neutrinos, and allows symmetry implications for measured deviations from
tri-bimaximal form to be studied systematically. Our approach does not depend
on choosing the rotation between the weak and mass eigenstates of the charged
lepton fields to be diagonal. We comment on using this expansion to examine the
symmetry implications of the recent results from the Daya-Bay collaboration
reporting the discovery of a non zero value for theta_{13}, indicating a
deviation from tri-bimaximal form, with a significance of 5.2 sigma.Comment: 16 pp, 1 figure v2: Jhep version, more exposition/description,results
  unchange
Exceptional Operators in N=4 super Yang-Mills

We consider one particularly interesting class of composite gauge-invariant
operators in N=4 super Yang-Mills theory. An exceptional feature of these
operators is that in the Thermodynamic Bethe Ansatz approach the one-loop
rapidities of the constituent magnons are shown to be exact in the 't Hooft
coupling constant. This is used to propose the mirror TBA description for these
operators. The proposal is shown to pass several non-trivial checks.Comment: 40 pages, 2 figures, 1 attached Mathematica noteboo
Conformally coupled scalar black holes admit a flat horizon due to
  axionic charge

Static, charged black holes in the presence of a negative cosmological
constant and with a planar horizon are found in four dimensions. The solutions
have scalar secondary hair. We claim that these constitute the planar version
of the Martinez-Troncoso-Zanelli black holes, only known up to now for a curved
event horizon in four dimensions. Their planar version is rendered possible due
to the presence of two, equal and homogeneously distributed, axionic charges
dressing the flat horizon. The solutions are presented in the conformal and
minimal frame and their basic properties and thermodynamics analysed.
Entertaining recent applications to holographic superconductors, we expose two
branches of solutions: the undressed axionic Reissner-Nordstrom-AdS black hole,
and the novel black hole carrying secondary hair. We show that there is a
critical temperature at which the (bald) axionic Reissner-Nordstrom-AdS black
hole undergoes a second order phase transition to the hairy black hole
spontaneously acquiring scalar hair.Comment: 21 pages, 4 figure
Lorentz-violating vs ghost gravitons: the example of Weyl gravity

We show that the ghost degrees of freedom of Einstein gravity with a Weyl
term can be eliminated by a simple mechanism that invokes local Lorentz
symmetry breaking. We demonstrate how the mechanism works in a cosmological
setting. The presence of the Weyl term forces a redefinition of the quantum
vacuum state of the tensor perturbations. As a consequence the amplitude of
their spectrum blows up when the Lorentz-violating scale becomes comparable to
the Hubble radius. Such a behaviour is in sharp contrast to what happens in
standard Weyl gravity where the gravitational ghosts smoothly damp out the
spectrum of primordial gravitational waves.Comment: 14 pages, 3 figures, REVTeX 4.
High-precision scale setting in lattice QCD

Scale setting is of central importance in lattice QCD. It is required to
predict dimensional quantities in physical units. Moreover, it determines the
relative lattice spacings of computations performed at different values of the
bare coupling, and this is needed for extrapolating results into the continuum.
Thus, we calculate a new quantity, $w_0$, for setting the scale in lattice QCD,
which is based on the Wilson flow like the scale $t_0$ (M. Luscher, JHEP 1008
(2010) 071). It is cheap and straightforward to implement and compute. In
particular, it does not involve the delicate fitting of correlation functions
at asymptotic times. It typically can be determined on the few per-mil level.
We compute its continuum extrapolated value in 2+1-flavor QCD for physical and
non-physical pion and kaon masses, to allow for mass-independent scale setting
even away from the physical mass point. We demonstrate its robustness by
computing it with two very different actions (one of them with staggered, the
other with Wilson fermions) and by showing that the results agree for physical
quark masses in the continuum limit.Comment: 15 pages, 7 figures, 2 tables; Version published in JHE
Higher-derivative scalar-vector-tensor theories: black holes, Galileons,
  singularity cloaking and holography

We consider a general Kaluza-Klein reduction of a truncated Lovelock theory.
We find necessary geometric conditions for the reduction to be consistent. The
resulting lower-dimensional theory is a higher derivative scalar-tensor theory,
depends on a single real parameter and yields second-order field equations. Due
to the presence of higher-derivative terms, the theory has multiple
applications in modifications of Einstein gravity (Galileon/Horndesky theory)
and holography (Einstein-Maxwell-Dilaton theories). We find and analyze charged
black hole solutions with planar or curved horizons, both in the 'Einstein' and
'Galileon' frame, with or without cosmological constant. Naked singularities
are dressed by a geometric event horizon originating from the higher-derivative
terms. The near-horizon region of the near-extremal black hole is unaffected by
the presence of the higher derivatives, whether scale invariant or hyperscaling
violating. In the latter case, the area law for the entanglement entropy is
violated logarithmically, as expected in the presence of a Fermi surface. For
negative cosmological constant and planar horizons, thermodynamics and
first-order hydrodynamics are derived: the shear viscosity to entropy density
ratio does not depend on temperature, as expected from the higher-dimensional
scale invariance.Comment: v2: matches published version; typos corrected, references and
  comments added, in particular regarding violation of the area law of the
  entanglement entrop
Membrane Sigma-Models and Quantization of Non-Geometric Flux Backgrounds

We develop quantization techniques for describing the nonassociative geometry
probed by closed strings in flat non-geometric R-flux backgrounds M. Starting
from a suitable Courant sigma-model on an open membrane with target space M,
regarded as a topological sector of closed string dynamics in R-space, we
derive a twisted Poisson sigma-model on the boundary of the membrane whose
target space is the cotangent bundle T^*M and whose quasi-Poisson structure
coincides with those previously proposed. We argue that from the membrane
perspective the path integral over multivalued closed string fields in Q-space
is equivalent to integrating over open strings in R-space. The corresponding
boundary correlation functions reproduce Kontsevich's deformation quantization
formula for the twisted Poisson manifolds. For constant R-flux, we derive
closed formulas for the corresponding nonassociative star product and its
associator, and compare them with previous proposals for a 3-product of fields
on R-space. We develop various versions of the Seiberg-Witten map which relate
our nonassociative star products to associative ones and add fluctuations to
the R-flux background. We show that the Kontsevich formula coincides with the
star product obtained by quantizing the dual of a Lie 2-algebra via convolution
in an integrating Lie 2-group associated to the T-dual doubled geometry, and
hence clarify the relation to the twisted convolution products for topological
nonassociative torus bundles. We further demonstrate how our approach leads to
a consistent quantization of Nambu-Poisson 3-brackets.Comment: 52 pages; v2: references adde
Enhancing lepton flavour violation in the supersymmetric inverse seesaw
  beyond the dipole contribution

In minimal supersymmetric models the $Z$-penguin usually provides
sub-dominant contributions to charged lepton flavour violating observables. In
this study, we consider the supersymmetric inverse seesaw in which the
non-minimal particle content allows for dominant contributions of the
$Z$-penguin to several lepton flavour violating observables. In particular, and
due to the low-scale (TeV) seesaw, the penguin contribution to, for instance,
$\Br(\mu \to 3e)$ and $\mu-e$ conversion in nuclei, allows to render some of
these observables within future sensitivity reach. Moreover, we show that in
this framework, the $Z$-penguin exhibits the same non-decoupling behaviour
which had previously been identified in flavour violating Higgs decays in the
Minimal Supersymmetric Standard Model.Comment: 29 pages, 9 figures, 4 tables; v2: minor corrections, version to
  appear in JHE
Non-Abelian Self-Dual String Solutions

We consider the equations of motion of the non-abelian 5-branes theory
recently constructed in http://arxiv.org/abs/arXiv:1203.4224 and find exact
string solutions both for uncompactified and compactified spacetime. Although
one does not have the full supersymmetric construction of the non-abelian (2,0)
theory, by combining knowledge of conformal symmetry and R-symmetry one can
argue for the form of the 1/2 BPS equations in the case when only one scalar
field is turned on. We solve this system and show that our string solutions
could be lifted to become solutions of the non-abelian (2,0) theory with
self-dual electric and magnetic charges, with the scalar field describing a
M2-brane spike emerging out of the multiple M5-branes worldvolume.Comment: 22 pages. LaTeX. 2 figure
A geometric bound on F-term inflation

We discuss a general bound on the possibility to realise inflation in any
minimal supergravity with F-terms. The derivation crucially depends on the
sGoldstini, the scalar field directions that are singled out by spontaneous
supersymmetry breaking. The resulting bound involves both slow-roll parameters
and the geometry of the K\"ahler manifold of the chiral scalars. We analyse the
inflationary implications of this bound, and in particular discuss to what
extent the requirements of single field and slow-roll can both be met in F-term
inflation.Comment: 14 pages, improved analysis, references added, matches published
  versio