pinecone/core-2020-05-10-deduplication huggingface dataset:
N=1 Deformations and RG Flows of N=2 SCFTs, Part II: Non-principal
  deformations

We continue to investigate the $\mathcal{N}=1$ deformations of
four-dimensional $\mathcal{N}=2$ superconformal field theories (SCFTs) labeled
by a nilpotent element of the flavor symmetry. This triggers a renormalization
group (RG) flow to an $\mathcal{N}=1$ SCFT. We systematically analyze all
possible deformations of this type for certain classes of $\mathcal{N}=2$
SCFTs: conformal SQCDs, generalized Argyres-Douglas theories and the $E_6$
SCFT. We find a number of examples where the amount of supersymmetry gets
enhanced to $\mathcal{N}=2$ at the end point of the RG flow. Most notably, we
find that the $SU(N)$ and $Sp(N)$ conformal SQCDs can be deformed to flow to
the Argyres-Douglas (AD) theories of type $(A_1, D_{2N-1})$ and $(A_1, D_{2N})$
respectively. This RG flow therefore allows us to compute the full
superconformal index of the $(A_1,D_N)$ class of AD theories. Moreover, we find
an infrared duality between $\mathcal{N}=1$ theories where the fixed point is
described by an $\mathcal{N}=2$ AD theory. We observe that the classes of
examples that exhibit supersymmetry enhancement saturate certain bounds for the
central charges implied by the associated two-dimensional chiral algebra.Comment: 46 pages, 12 tables, typos corrected and some minor change
Multi-particle correlations and KNO scaling in the medium-induced jet
  evolution

We study the gluon distribution produced via successive medium-induced
branchings by an energetic jet propagating through a weakly-coupled quark-gluon
plasma. We show that under suitable approximations the evolution of the jet can
be described as a classical stochastic process, which is exactly solvable. For
this process, we construct exact analytic solutions for all the n-point
correlation functions (the n-body densities in the space of energy). The
corresponding results for the one-point and the two-point functions were
already known, but those for the higher-point functions are new. These results
demonstrate strong correlations associated with the existence of common
ancestors in the branching process. By integrating these n-point functions over
the gluon energies, we deduce the mean gluon multiplicity $\langle N\rangle$ as
well as the higher moments $\langle N^p\rangle$ with $p\ge 2$. We find that the
multiplicities of the soft gluons are parametrically large and show a
remarkable regularity, known as Koba-Nielsen-Olesen (KNO) scaling: the reduced
moments $\langle N^p\rangle/\langle N\rangle^p$ are pure numbers, independent
of any of the physical parameters of the problem. We recognize a special
negative binomial distribution which is characterized by large statistical
fluctuations. These predictions can be tested in Pb+Pb collisions at the LHC,
via event-by-event measurements of the di-jet asymmetry.Comment: 31 pages, 7 figure
Explaining Dark Matter and $B$ Decay Anomalies with an $L_\mu - L_\tau$
  Model

We present a dark sector model based on gauging the $L_\mu - L_\tau$ symmetry
that addresses anomalies in $b \rightarrow s \mu^+ \mu^-$ decays and that
features a particle dark matter candidate. The dark matter particle candidate
is a vector-like Dirac fermion coupled to the $Z^\prime$ gauge boson of the
$L_{\mu}-L_{\tau}$ symmetry. We compute the dark matter thermal relic density,
its pair-annihilation cross section, and the loop-suppressed dark
matter-nucleon scattering cross section, and compare our predictions with
current and future experimental results. We demonstrate that after taking into
account bounds from $B_s$ meson oscillations, dark matter direct detection, and
the CMB, the model is highly predictive: $B$ physics anomalies and a viable
particle dark matter candidate, with a mass of $\sim (5-23)$~GeV, can be
accommodated only in a tightly-constrained region of parameter space, with
sharp predictions for future experimental tests. The viable region of parameter
space expands if the dark matter is allowed to have $L_\mu-L_\tau$ charges that
are smaller than those of the SM leptons.Comment: 27 pages, 6 figures. Matches published versio
On Effective Holographic Mott Insulators

We present a class of holographic models that behave effectively as
prototypes of Mott insulators, materials where electron-electron interactions
dominate transport phenomena. The main ingredient in the gravity dual is that
the gauge-field dynamics contains self-interactions by way of a particular type
of non-linear electrodynamics. The electrical response in these models exhibits
typical features of Mott-like states: i) the low-temperature DC conductivity is
unboundedly low; ii) metal-insulator transitions appear by varying various
parameters; iii) for large enough self-interaction strength, the conductivity
can even decrease with increasing doping (density of carriers), which appears
as a sharp manifestation of `traffic-jam'-like behaviour; iv) the insulating
state becomes very unstable towards superconductivity at large enough doping.
We exhibit some of the properties of the resulting insulator-superconductor
transition, which is sensitive to the amount of disorder in a specific way.
These models imply a clear and generic correlation between Mott behaviour and
significant effects in the nonlinear electrical response. We compute the
nonlinear current-voltage curve in our model and find that indeed at large
voltage the conductivity is largely reduced.Comment: 48 pages, 16 figure
Partially Acoustic Dark Matter, Interacting Dark Radiation, and Large
  Scale Structure

The standard paradigm of collisionless cold dark matter is in tension with
measurements on large scales. In particular, the best fit values of the Hubble
rate $H_0$ and the matter density perturbation $\sigma_8$ inferred from the
cosmic microwave background seem inconsistent with the results from direct
measurements. We show that both problems can be solved in a framework in which
dark matter consists of two distinct components, a dominant component and a
subdominant component. The primary component is cold and collisionless. The
secondary component is also cold, but interacts strongly with dark radiation,
which itself forms a tightly coupled fluid. The growth of density perturbations
in the subdominant component is inhibited by dark acoustic oscillations due to
its coupling to the dark radiation, solving the $\sigma_8$ problem, while the
presence of tightly coupled dark radiation ameliorates the $H_0$ problem. The
subdominant component of dark matter and dark radiation continue to remain in
thermal equilibrium until late times, inhibiting the formation of a dark disk.
We present an example of a simple model that naturally realizes this scenario
in which both constituents of dark matter are thermal WIMPs. Our scenario can
be tested by future stage-IV experiments designed to probe the CMB and large
scale structure.Comment: 10 pages, 3 figures; matches version published in JHE
Looking into Analytical Approximations for Three-flavor Neutrino
  Oscillation Probabilities in Matter

Motivated by tremendous progress in neutrino oscillation experiments, we
derive a new set of simple and compact formulas for three-flavor neutrino
oscillation probabilities in matter of a constant density. A useful definition
of the $\eta$-gauge neutrino mass-squared difference $\Delta^{}_* \equiv \eta
\Delta^{}_{31} + (1-\eta) \Delta^{}_{32}$ is introduced, where $\Delta^{}_{ji}
\equiv m^2_j - m^2_i$ for $ji = 21, 31, 32$ are the ordinary neutrino
mass-squared differences and $0 \leq \eta \leq 1$ is a real and positive
parameter. Expanding neutrino oscillation probabilities in terms of $\alpha
\equiv \Delta^{}_{21}/\Delta^{}_*$, we demonstrate that the analytical formulas
can be remarkably simplified for $\eta = \cos^2 \theta^{}_{12}$, with
$\theta_{12}^{}$ being the solar mixing angle. As a by-product, the mapping
from neutrino oscillation parameters in vacuum to their counterparts in matter
is obtained at the order of ${\cal O}(\alpha^2)$. Finally, we show that our
approximate formulas are not only valid for an arbitrary neutrino energy and
any baseline length, but also still maintaining a high level of accuracy.Comment: 34 pages, 5 figures; v2: reference added, to appear in JHE
On CFT and Quantum Chaos

We make three observations that help clarify the relation between CFT and
quantum chaos. We show that any 1+1-D system in which conformal symmetry is
non-linearly realized exhibits two main characteristics of chaos: maximal
Lyapunov behavior and a spectrum of Ruelle resonances. We use this insight to
identify a lattice model for quantum chaos, built from parafermionic spin
variables with an equation of motion given by a Y-system. Finally we point to a
relation between the spectrum of Ruelle resonances of a CFT and the analytic
properties of OPE coefficients between light and heavy operators. In our model,
this spectrum agrees with the quasi-normal modes of the BTZ black hole.Comment: 26 pages, 2 figures. References adde
$H \rightarrow \tau^+ \tau^- \gamma$ as a Probe of the $\tau$ Magnetic
  Dipole Moment

Low energy observables involving the Standard Model fermions which are
chirality-violating, such as anomalous electromagnetic moments, necessarily
involve an insertion of the Higgs in order to maintain $SU(2) \times U(1)$
gauge invariance. As the result, the properties of the Higgs boson measured at
the LHC impact our understanding of the associated low-energy quantities. We
illustrate this feature with a discussion of the electromagnetic moments of the
$\tau$-lepton, as probed by the rare decay $H \rightarrow \tau^+ \tau^-
\gamma$. We assess the feasibility of measuring this decay at the LHC, and show
that the current bounds from lower energy measurements imply that $13~\rm{TeV}$
running is very likely to improve our understanding of new physics contributing
to the anomalous magnetic moment of the tau.Comment: 13 pages, 3 figure
Non-Abelian black string solutions of N=(2,0),d=6 supergravity

We show that, when compactified on a circle, N=(2,0),d=6 supergravity coupled
to 1 tensor multiplet and nV vector multiplets is dual to N=(2,0),d=6
supergravity coupled to just nT=nV+1 tensor multiplets and no vector
multiplets. Both theories reduce to the same models of N=2,d=5 supergravity
coupled to nV5=nV+2 vector fields. We derive Buscher rules that relate
solutions of these theories (and of the theory that one obtains by dualizing
the 3-form field strength) admitting an isometry. Since the relations between
the fields of N=2,d=5 supergravity and those of the 6-dimensional theories are
the same with or without gaugings, we construct supersymmetric non-Abelian
solutions of the 6-dimensional gauged theories by uplifting the recently found
5-dimensional supersymmetric non-Abelian black-hole solutions. The solutions
describe the usual superpositions of strings and waves supplemented by a BPST
instanton in the transverse directions. One of the solutions obtained
interpolates smoothly between two AdS3xS3 geometries with different radii.Comment: A few typos corrected in text and formulae. Version to be published
  in JHE
The large D black hole Membrane Paradigm at first subleading order

In the large D limit, and under certain circumstances, it has recently been
demonstrated that black hole dynamics in asymptotically flat spacetime reduces
to the dynamics of a non gravitational membrane propagating in flat D
dimensional spacetime. We demonstrate that this correspondence extends to all
orders in a 1/D expansion and outline a systematic method for deriving the
corrected membrane equation in a power series expansion in 1/D. As an
illustration of our method we determine the first subleading corrections to the
membrane equations of motion. A qualitatively new effect at this order is that
the divergence of the membrane velocity is nonzero and proportional to the
square of the shear tensor reminiscent of the entropy current of hydrodynamics.
As a test, we use our modified membrane equations to compute the corrections to
frequencies of light quasinormal modes about the Schwarzschild black hole and
find a perfect match with earlier computations performed directly in the
gravitational bulk.Comment: Typesetting corrected, New appendix added to explain the method of
  computatio
$P$ fluxes and exotic branes

We consider the ${\cal N}=1$ superpotential generated in type-II orientifold
models by non-geometric fluxes. In particular, we focus on the family of $P$
fluxes, that are related by T-duality transformations to the S-dual of the $Q$
flux. We determine the general rule that transforms a given flux in this family
under a single T-duality transformation. This rule allows to derive a complete
expression for the superpotential for both the IIA and the IIB theory for the
particular case of a $T^6/[\mathbb{Z}_2 \times \mathbb{Z}_2 ]$ orientifold. We
then consider how these fluxes modify the generalised Bianchi identities. In
particular, we derive a fully consistent set of quadratic constraints coming
from the NS-NS Bianchi identities. On the other hand, the $P$ flux Bianchi
identities induce tadpoles, and we determine a set of exotic branes that can be
consistently included in order to cancel them. This is achieved by determining
a universal transformation rule under T-duality satisfied by all the branes in
string theory.Comment: 29 pages. Refs. added, end of subsection 4.2 improved, other minor
  changes. Version published on JHE
Off-Shell Spinor-Helicity Amplitudes from Light-Cone Deformation
  Procedure

We study the consistency conditions for interactions of massless fields of
any spin in four-dimensional flat space using the light-cone approach. We show
that they can be equivalently rewritten as the Ward identities for the
off-shell light-cone amplitudes built from the light-cone Hamiltonian in the
standard way. Then we find a general solution of these Ward identities. The
solution admits a compact representation when written in the spinor-helicity
form and is given by an arbitrary function of spinor products, satisfying
well-known homogeneity constraints. Thus, we show that the light-cone
consistent deformation procedure inevitably leads to a certain off-shell
version of the spinor-helicity approach. We discuss how the relation between
the two approaches can be employed to facilitate the search of consistent
interaction of massless higher-spin fields.Comment: 34 pages, discussion on locality extended, references added, version
  to appear in JHE
Gauged Lepton Flavour

The gauging of the lepton flavour group is considered in the Standard Model
context and in its extension with three right-handed neutrinos. The anomaly
cancellation conditions lead to a Seesaw mechanism as underlying dynamics for
all leptons; requiring in addition a phenomenologically viable setup leads to
Majorana masses for the neutral sector: the type I Seesaw Lagrangian in the
Standard Model case and the inverse Seesaw in the extended model. Within the
minimal extension of the scalar sector, the Yukawa couplings are promoted to
scalar fields in the bifundamental of the flavour group. The resulting
low-energy Yukawa couplings are proportional to inverse powers of the vacuum
expectation values of those scalars; the protection against flavour changing
neutral currents differs from that of Minimal Flavor Violation. In all cases,
the $\mu-\tau$ flavour sector exhibits rich and promising phenomenological
signals.Comment: 42 pages, 9 figures, 2 tables; revised argument in section 2, results
  unchanged, references adde
Operator Mixing in Large $N$ Superconformal Field Theories on
  $\mathbb{S}^4$ and Correlators with Wilson loops

We find a general formula for the operator mixing on the $\mathbb{S}^4$ of
chiral primary operators (CPO) for the ${\cal N}=4$ theory at large $N$ in
terms of Chebyshev polynomials. As an application, we compute the correlator of
a CPO and a Wilson loop, reproducing an earlier result by Giombi and Pestun
obtained from a two-matrix model proposal. Finally, we discuss a simple method
to obtain correlators in general ${\cal N}=2$ superconformal field theories in
perturbation theory in terms of correlators of the ${\cal N}=4$ theory.Comment: 15 pages, no figure
Non-abelian factorisation for next-to-leading-power threshold logarithms

Soft and collinear radiation is responsible for large corrections to many
hadronic cross sections, near thresholds for the production of heavy final
states. There is much interest in extending our understanding of this radiation
to next-to-leading power (NLP) in the threshold expansion. In this paper, we
generalise a previously proposed all-order NLP factorisation formula to include
non-abelian corrections. We define a non-abelian radiative jet function,
organising collinear enhancements at NLP, and compute it for quark jets at one
loop. We discuss in detail the issue of double counting between soft and
collinear regions. Finally, we verify our prescription by reproducing all NLP
logarithms in Drell-Yan production up to NNLO, including those associated with
double real emission. Our results constitute an important step in the
development of a fully general resummation formalism for NLP threshold effects.Comment: 17 pages, 4 figure
Quark--anti-quark potential in N=4 SYM

We construct a closed system of equations describing the quark--anti-quark
potential at any coupling in planar N=4 supersymmetric Yang-Mills theory. It is
based on the Quantum Spectral Curve method supplemented with a novel type of
asymptotics. We present a high precision numerical solution reproducing the
classical and one-loop string predictions very accurately. We also analytically
compute the first 7 nontrivial orders of the weak coupling expansion.
  Moreover, we study analytically the generalized quark--anti-quark potential
in the limit of large imaginary twist to all orders in perturbation theory. We
demonstrate how the QSC reduces in this case to a one-dimensional Schrodinger
equation. In the process we establish a link between the Q-functions and the
solution of the Bethe-Salpeter equation.Comment: 31 pages, 1 figure; v2: minor correcton
Entanglement entropy after selective measurements in quantum chains

We study bipartite post measurement entanglement entropy after selective
measurements in quantum chains. We first study the quantity for the critical
systems that can be described by conformal field theories. We find a connection
between post measurement entanglement entropy and the Casimir energy of
floating objects. Then we provide formulas for the post measurement
entanglement entropy for open and finite temperature systems. We also comment
on the Affleck-Ludwig boundary entropy in the context of the post measurement
entanglement entropy. Finally, we also provide some formulas regarding modular
hamiltonians and entanglement spectrum in the after measurement systems. After
through discussion regarding CFT systems we also provide some predictions
regarding massive field theories. We then discuss a generic method to calculate
the post measurement entanglement entropy in the free fermion systems. Using
the method we study the post measurement entanglement entropy in the XY spin
chain. We check numerically the CFT and the massive field theory results in the
transverse field Ising chain and the XX model. In particular, we study the post
meaurement entanglement entropy in the infinite, periodic and open critical
transverse field Ising chain and the critical XX model. The effect of the
temperature and the gap is also discussed in these models.Comment: Published version: 71 pages, 36 figures. added new references
Revisiting AdS/CFT at a finite radial cut-off

We revisit AdS/CFT at finite radial cut-off, specifically in the context of
double trace perturbations, $\mathbb{O}_n$= $\mathbb{O}(x) (\partial^2)^{n}
{\mathcal O}(x)$, with arbitrary $n$. As well-known, the standard GKPW
prescription, applied to a finite radial cut-off, leads to contact terms in
correlators. de Haro et al (arXiv:hep-th/0002230) introduced bulk counterterms
to remove these. However, this prescription yields additional terms in the
correlator corresponding to spurious double trace deformations. Further, if we
view GKPW prescription coupled with the prescription in arXiv:hep-th/0002230,
in terms of a boundary wavefunction, we find that it is incompatible with
radial Schrodinger evolution (in the spirit of holographic Wilsonian RG). We
consider a more general wavefunction satisfying the Schrodinger equation, and
find that generically such wavefunctions generate both (a) double trace
deformations and (b) contact terms. However, we find that there exist special
choices of these wavefunctions, amounting to a new AdS/CFT prescription at a
finite cut-off, so that both (a) and (b) are removed and we obtain a pure power
law behaviour for the correlator. We compare these special wavefunctions with a
specific RG scheme in field theory. We give a geometric interpretation of these
wavefunctions; these correspond to some specific smearing of boundary points in
the Witten diagrams. We present a comprehensive calculation of exact
double-trace beta-functions for all couplings $\mathbb{O}_n$ and match with a
holographic computation using the method described above. The matching works
with a mapping between the field theory and bulk couplings; such a map is
highly constrained because the beta-functions are quadratic and exact on both
sides. We generalize standard double-trace Wilson-Fisher flow to the space of
the infinite number of couplings.Comment: 45+2 pages, 10 figures, typesetting errors correcte
Classification of certain asymptotically AdS space-times with Ricci-flat
  boundary

We classify solutions to Einstein's equations in AdS with Ricci-flat boundary
metric and with covariantly constant boundary stress tensor, which in general
is not diagonalizable, i.e. it does not admit a reference frame. New solutions
are found, and in the context of the AdS/CFT duality they should describe a
boundary QFT in certain non-equilibrium steady states. Further imposing the
absence of scalar curvature singularities leads to a subset of metrics that can
be seen as null deformations of AdS or of the AdS soliton. We also outline the
procedure of solving the equations when a scalar is coupled to the metric,
which holographically leads to non-Lorentz-invariant RG flows.Comment: 30 pages; v2: two references added, typos corrected, some
  explanations improved; v.3: title changed, minor modifications of the
  abstract, improved introduction of secs. II and V, three references added,
  two typos corrected (published version
Hydrogen Axion Star: Metallic Hydrogen Bound to a QCD Axion BEC

As a cold dark matter candidate, the QCD axion may form Bose-Einstein
condensates, called axion stars, with masses around $10^{-11}\,M_{\odot}$. In
this paper, we point out that a brand new astrophysical object, a Hydrogen
Axion Star (HAS), may well be formed by ordinary baryonic matter becoming
gravitationally bound to an axion star. We study the properties of the HAS and
find that the hydrogen cloud has a high pressure and temperature in the center
and is likely in the liquid metallic hydrogen state. Because of the high
particle number densities for both the axion star and the hydrogen cloud, the
feeble interaction between axion and hydrogen can still generate enough
internal power, around $10^{13}~\mbox{W}\times(m_a/5~\mbox{meV})^4$, to make
these objects luminous point sources. High resolution ultraviolet, optical and
infrared telescopes can discover HAS via black-body radiation.Comment: 35 pages, 7 figure