pinecone/core-2020-05-10-deduplication huggingface dataset:
Emergent Lorentz symmetry near fermionic quantum critical points in two
  and three dimensions

We study the renormalization group flow of the velocities in the field theory
describing the coupling of the massless quasi-relativistic fermions to the
bosons through the Yukawa coupling, as well as with both bosons and fermions
coupled to a fluctuating $U(1)$ gauge field in two and three spatial
dimensions. Different versions of this theory describe quantum critical
behavior of interacting Dirac fermions in various condensed-matter systems. We
perform an analysis using one-loop $\epsilon-$expansion about three spatial
dimensions, which is the upper critical dimension in the problem. In two
dimensions, we find that velocities of both charged fermions and bosons
ultimately flow to the velocity of light, independently of the initial
conditions, the number of fermionic and bosonic flavors, and the value of the
couplings at the critical point. In three dimensions, due to the analyticity of
the gauge field propagator, both the $U(1)$ charge and the velocity of light
flow, which leads to a richer behavior than in two dimensions. We show that all
three velocities ultimately flow to a common terminal velocity, which is
non-universal and different from the original velocity of light. Therefore,
emergence of the Lorentz symmetry in the ultimate infrared regime seems to be a
rather universal feature of this class of theories in both two and three
dimensions.Comment: 19 pages, 4 figures: Published version, added discussion, new
  references, typos correcte
G2HDM : Gauged Two Higgs Doublet Model

A novel model embedding the two Higgs doublets in the popular two Higgs
doublet models into a doublet of a non-abelian gauge group $SU(2)_H$ is
presented. The Standard Model $SU(2)_L$ right-handed fermion singlets are
paired up with new heavy fermions to form $SU(2)_H$ doublets, while $SU(2)_L$
left-handed fermion doublets are singlets under $SU(2)_H$. Distinctive features
of this anomaly-free model are: (1) Electroweak symmetry breaking is induced
from spontaneous symmetry breaking of $SU(2)_H$ via its triplet vacuum
expectation value; (2) One of the Higgs doublet can be inert, with its neutral
component being a dark matter candidate as protected by the $SU(2)_H$ gauge
symmetry instead of a discrete $Z_2$ symmetry in the usual case; (3) Unlike
Left-Right Symmetric Models, the complex gauge fields $(W_1^{\prime}\mp i
W_2^{\prime})$ (along with other complex scalar fields) associated with the
$SU(2)_H$ do {\it not} carry electric charges, while the third component
$W^{\prime}_3$ can mix with the hypercharge $U(1)_Y$ gauge field and the third
component of $SU(2)_L$; (4) Absence of tree level flavour changing neutral
current is guaranteed by gauge symmetry; and {\it etc}. In this work, we
concentrate on the mass spectra of scalar and gauge bosons in the model.
Constraints from previous $Z^\prime$ data at LEP and the Large Hadron Collider
measurements of the Standard Model Higgs mass, its partial widths of
$\gamma\gamma$ and $Z\gamma$ modes are discussed.Comment: 40 pages, 7 figures, version accepted in JHEP, relic density
  discussion adde
Relaxion Monodromy and the Weak Gravity Conjecture

The recently proposed relaxion models require extremely large trans-Planckian
axion excursions as well as a potential explicitly violating the axion shift
symmetry. The latter property is however inconsistent with the axion
periodicity, which corresponds to a gauged discrete shift symmetry. A way to
make things consistent is to use monodromy, i.e. both the axion and the
potential parameters transform under the discrete shift symmetry. The structure
is better described in terms of a 3-form field $C_{\mu \nu \rho}$ coupling to
the SM Higgs through its field strength $F_4$. The 4-form also couples linearly
to the relaxion, in the Kaloper-Sorbo fashion. The extremely small
relaxion-Higgs coupling arises in a see-saw fashion as $g\simeq F_4/f$, with
$f$ being the axion decay constant. We discuss constraints on this type of
constructions from membrane nucleation and the Weak Gravity Conjecture. The
latter requires the existence of membranes, whose too fast nucleation could in
principle drive the theory out of control, unless the cut-off scale is lowered.
This allows to constrain relaxion models on purely theoretical grounds. We also
discuss possible avenues to embed this structure into string theory.Comment: 26 pages + appendices, 3 figures; v3: Corrected bounds on relaxion
  parameter spac
Thermal conductivity at a disordered quantum critical point

Strongly disordered and strongly interacting quantum critical points are
difficult to access with conventional field theoretic methods. They are,
however, both experimentally important and theoretically interesting. In
particular, they are expected to realize universal incoherent transport. Such
disordered quantum critical theories have recently been constructed
holographically by deforming a CFT by marginally relevant disorder. In this
paper we find additional disordered fixed points via relevant disordered
deformations of a holographic CFT. Using recently developed methods in
holographic transport, we characterize the thermal conductivity in both sets of
theories in 1+1 dimensions. The thermal conductivity is found to tend to a
constant at low temperatures in one class of fixed points, and to scale as
$T^{0.3}$ in the other. Furthermore, in all cases the thermal conductivity
exhibits discrete scale invariance, with logarithmic in temperature
oscillations superimposed on the low temperature scaling behavior. At no point
do we use the replica trick.Comment: 1+28 pages. 6 figure
Scalar Dark Matter in Scale Invariant Standard Model

We investigate single and two-component scalar dark matter scenarios in
classically scale invariant standard model which is free of the hierarchy
problem in the Higgs sector. We show that despite the very restricted space of
parameters imposed by the scale invariance symmetry, both single and
two-component scalar dark matter models overcome the direct and indirect
constraints provided by the Planck/WMAP observational data and the LUX/Xenon100
experiment. We comment also on the radiative mass corrections of the
classically massless scalon that plays a crucial role in our study.Comment: 11 pages, 6 figures. 2 figures added, typos fixe
Enhanced Higgs Mass in Compact Supersymmetry

The current LHC results make weak scale supersymmetry difficult due to
relatively heavy mass of the discovered Higgs boson and the null results of new
particle searches. Geometrical supersymmetry breaking from extra dimensions,
Scherk-Schwarz mechanism, is possible to accommodate such situations. A
concrete example, the Compact Supersymmetry model, has a compressed spectrum
ameliorating the LHC bounds and large mixing in the top and scalar top quark
sector with $|A_t|\sim 2m_{\tilde{t}}$ which radiatively raises the Higgs mass.
While the zero mode contribution of the model has been considered, in this
paper we calculate the Kaluza-Klein tower effect to the Higgs mass. Although
such contributions are naively expected to be as small as a percent level for
10 TeV Kaluza-Klein modes, we find the effect significantly enhances the
radiative correction to the Higgs quartic coupling by from 10 to 50 %. This is
mainly because the top quark wave function is pushed out from the brane, which
makes the top mass depend on higher powers in the Higgs field. As a result the
Higgs mass is enhanced up to 15 GeV from the previous calculation. We also show
the whole parameter space is testable at the LHC run II.Comment: 30 pages, 8 figures, appendix C added, conclusion unchanged, journal
  versio
The Hot Attractor Mechanism: Decoupling Without Deep Throats

Non-extremal black holes in $\mathcal{N}=2$ supergravity have two horizons,
the geometric mean of whose areas recovers the horizon area of the extremal
black hole obtained from taking a smooth zero temperature limit. In prior work
(arxiv:1410.3478), using the attractor mechanism, we deduced the existence of
several moduli independent invariant quantities obtained from averaging over a
decoupled inter-horizon region. We establish that non-extremal geometries at
the Reissner--Nordstr\"om point, where the scalar moduli are held fixed, can be
lifted to solutions in supergravity with a near-horizon AdS$_3\times$S$^2$.
These solutions have the same entropy and temperature as the original black
hole and therefore allow an interpretation of the underlying gravitational
degrees of freedom in terms of CFT$_2$. Symmetries of the moduli space enable
us to explicate the origin of entropy in the extremal limit.Comment: References adde
Coupling the Inflationary Sector to Matter

We describe the coupling of matter fields to an inflationary sector of
supergravity, the inflaton $\Phi$ and a stabilizer $S$, in models where the
Kahler potential has a flat inflaton direction. Such models include, in
particular, advanced versions of the hyperbolic $\alpha$-attractor models with
a flat inflaton direction Kahler potential, providing a good fit to the
observational data. If the superpotential is at least quadratic in the matter
fields $U^{i}$, with restricted couplings to the inflaton sector, we prove that
under certain conditions: i) The presence of the matter fields does not affect
a successful inflationary evolution. ii) There are no tachyons in the matter
sector during and after inflation. iii) The matter masses squared are higher
than $3H^2$ during inflation. The simplest class of theories satisfying all
required conditions is provided by models with a flat direction Kahler
potential, and with the inflaton $\Phi$ and a stabilizer $S$ belonging to a
hidden sector, so that matter fields have no direct coupling to the
inflationary sector in the Kahler potential and in the superpotential.Comment: 19 pages, minor modification
f(Lovelock) theories of gravity

f(Lovelock) gravities are simple generalizations of the usual f(R) and
Lovelock theories in which the gravitational action depends on some arbitrary
function of the corresponding dimensionally-extended Euler densities. In this
paper we study several aspects of these theories in general dimensions. We
start by identifying the generalized boundary term which makes the
gravitational variational problem well-posed. Then, we show that these theories
are equivalent to certain scalar-tensor theories and how this relation is
characterized by the Hessian of f. We also study the linearized equations of
the theory on general maximally symmetric backgrounds. Remarkably, we find that
these theories do not propagate the usual ghost-like massive gravitons
characteristic of higher-derivative gravities on such backgrounds. In some
non-trivial cases, the additional scalar associated to the trace of the metric
perturbation is also absent, being the usual graviton the only dynamical field.
In those cases, the linearized equations are exactly the same as in Einstein
gravity up to an overall factor, making them appealing as holographic toy
models. We also find constraints on the couplings of a broad family of
five-dimensional f(Lovelock) theories using holographic entanglement entropy.
Finally, we construct new analytic asymptotically flat and AdS/dS black hole
solutions for some classes of f(Lovelock) gravities in various dimensions.Comment: 46 pages, no figures; v3: minor modifications to match published
  version, references adde
Strong Wilson polygons from the lodge of free and bound mesons

Previously predicted by the $S$-matrix bootstrap of the excitations over the
GKP quantum vacuum, the appearance of a new particle at strong coupling --
formed by one fermion and one anti-fermion -- is here confirmed: this
two-dimensional meson shows up, along with its infinite tower of bound states,
while analysing the fermionic contributions to the Operator Product Expansion
(collinear regime) of the Wilson null polygon loop. Moreover, its existence,
free \footnote{This term is used here as opposite to bound, thus as {\it
unbound}.} and bound, turns out to be a powerful idea in re-summing all the
contributions (at large coupling) for a general $n$-gon ($n\geq 6$) to a
Thermodynamic Bethe Ansatz, which is proven to be equivalent to the known one
and suggests new structures for a special $Y$-system.Comment: 38 pages, 3 figures; typos corrected, references added with slight
  improvement
Generalized Higher Gauge Theory

We study a generalization of higher gauge theory which makes use of
generalized geometry and seems to be closely related to double field theory.
The local kinematical data of this theory is captured by morphisms of graded
manifolds between the canonical exact Courant Lie 2-algebroid $TM\oplus T^*M$
over some manifold $M$ and a semistrict gauge Lie 2-algebra. We discuss
generalized curvatures and their infinitesimal gauge transformations. Finite
gauge transformation as well as global kinematical data are then obtained from
principal 2-bundles over 2-spaces. As dynamical principle, we consider first
the canonical Chern-Simons action for such a gauge theory. We then show that a
previously proposed 3-Lie algebra model for the six-dimensional (2,0) theory is
very naturally interpreted as a generalized higher gauge theory.Comment: 24 pages, minor corrections, typos fixed, published versio
Rotating Higher Spin Partition Functions and Extended BMS Symmetries

We evaluate one-loop partition functions of higher-spin fields in thermal
flat space with angular potentials; this computation is performed in arbitrary
space-time dimension, and the result is a simple combination of Poincar\'e
characters. We then focus on dimension three, showing that suitable products of
one-loop partition functions coincide with vacuum characters of higher-spin
asymptotic symmetry algebras at null infinity. These are extensions of the
bms_3 algebra that emerges in pure gravity, and we propose a way to build their
unitary representations and to compute the associated characters. We also
extend our investigations to supergravity and to a class of gauge theories
involving higher-spin fermionic fields.Comment: 58 pages; clarifications and references added; version to be
  published in JHE
Chiral Phase Transition in the Soft-Wall Model of AdS/QCD

We investigate the chiral phase transition in the soft-wall model of AdS/QCD
at zero chemical potential for two-flavor and three-flavor cases, respectively.
We show that there is no spontaneous chiral symmetry breaking in the original
soft-wall model. After detailed analysis, we find that in order to realize
chiral symmetry breaking and restoration, both profiles for the scalar
potential and the dilaton field are essential. The scalar potential determines
the possible solution structure of the chiral condensate, except the mass term,
it takes another quartic term for the two-flavor case, and for the three-flavor
case, one has to take into account an extra cubic term due to the t'Hooft
determinant interaction. The profile of the dilaton field reflects the
gluodynamics, which is negative at a certain ultraviolet scale and approaches
positive quadratic behavior at far infrared region. With this set-up, the
spontaneous chiral symmetry breaking in the vacuum and its restoration at
finite temperature can be realized perfectly. In the two-flavor case, it gives
a second order chiral phase transition in the chiral limit, while the
transition turns to be a crossover for any finite quark mass. In the case of
three-flavor, the phase transition becomes a first order one in the chiral
limit, while above sufficient large quark mass it turns to be a crossover
again. This scenario agrees exactly with the current understanding on chiral
phase transition from lattice QCD and other effective model studies.Comment: 31 pages,17 figure
An exploratory study of heavy domain wall fermions on the lattice

We report on an exploratory study of domain wall fermions (DWF) as a lattice
regularisation for heavy quarks. Within the framework of quenched QCD with the
tree-level improved Symanzik gauge action we identify the DWF parameters which
minimise discretisation effects. We find the corresponding effective 4$d$
overlap operator to be exponentially local, independent of the quark mass. We
determine a maximum bare heavy quark mass of $am_h\approx 0.4$, below which the
approximate chiral symmetry and O(a)-improvement of DWF are sustained. This
threshold appears to be largely independent of the lattice spacing. Based on
these findings, we carried out a detailed scaling study for the heavy-strange
meson dispersion relation and decay constant on four ensembles with lattice
spacings in the range $2.0-5.7\,\mathrm{GeV}$. We observe very mild $a^2$
scaling towards the continuum limit. Our findings establish a sound basis for
heavy DWF in dynamical simulations of lattice QCD with relevance to Standard
Model phenomenology.Comment: 23 pages, 8 figure
Heterotic free fermionic and symmetric toroidal orbifold models

Free fermionic models and symmetric heterotic toroidal orbifolds both
constitute exact backgrounds that can be used effectively for phenomenological
explorations within string theory. Even though it is widely believed that for
Z2xZ2 orbifolds the two descriptions should be equivalent, a detailed
dictionary between both formulations is still lacking. This paper aims to fill
this gap: We give a detailed account of how the input data of both descriptions
can be related to each other. In particular, we show that the generalized GSO
phases of the free fermionic model correspond to generalized torsion phases
used in orbifold model building. We illustrate our translation methods by
providing free fermionic realizations for all Z2xZ2 orbifold geometries in six
dimensions.Comment: 1+49 pages latex, minor revisions and references adde
Topological sigma models & dissipative hydrodynamics

We outline a universal Schwinger-Keldysh effective theory which describes
macroscopic thermal fluctuations of a relativistic field theory. The basic
ingredients of our construction are three: a doubling of degrees of freedom, an
emergent abelian symmetry associated with entropy, and a topological (BRST)
supersymmetry imposing fluctuation-dissipation theorem. We illustrate these
ideas for a non-linear viscous fluid, and demonstrate that the resulting
effective action obeys a generalized fluctuation-dissipation theorem, which
guarantees a local form of the second law.Comment: 22 pages. v2: added clarifications, fixed typos. v3: reference
  oversight fixe
On four dimensional N=3 superconformal theories

In this note we study four dimensional theories with N=3 superconformal
symmetry, that do not also have N=4 supersymmetry. No examples of such theories
are known, but their existence is also not ruled out. We analyze several
properties that such theories must have. We show that their conformal anomalies
obey a=c. Using the N=3 superconformal algebra, we show that they do not have
any exactly marginal deformations preserving N=3 supersymmetry, or global
symmetries (except for their R-symmetries). Finally, we analyze the possible
dimensions of chiral operators labeling their moduli space.Comment: 11 pages. v2 : corrected statement about exactly marginal
  deformations, added reference
Origin of Abelian Gauge Symmetries in Heterotic/F-theory Duality

We study aspects of heterotic/F-theory duality for compactifications with
Abelian gauge symmetries. We consider F-theory on general Calabi-Yau manifolds
with a rank one Mordell-Weil group of rational sections. By rigorously
performing the stable degeneration limit in a class of toric models, we derive
both the Calabi-Yau geometry as well as the spectral cover describing the
vector bundle in the heterotic dual theory. We carefully investigate the
spectral cover employing the group law on the elliptic curve in the heterotic
theory. We find in explicit examples that there are three different classes of
heterotic duals that have U(1) factors in their low energy effective theories:
split spectral covers describing bundles with S(U(m) x U(1)) structure group,
spectral covers containing torsional sections that seem to give rise to bundles
with SU(m) x Z_k structure group and bundles with purely non-Abelian structure
groups having a centralizer in E_8 containing a U(1) factor. In the former two
cases, it is required that the elliptic fibration on the heterotic side has a
non-trivial Mordell-Weil group. While the number of geometrically massless
U(1)'s is determined entirely by geometry on the F-theory side, on the
heterotic side the correct number of U(1)'s is found by taking into account a
Stuckelberg mechanism in the lower-dimensional effective theory. In geometry,
this corresponds to the condition that sections in the two half K3 surfaces
that arise in the stable degeneration limit of F-theory can be glued together
globally.Comment: 52 pages, 15 figure
Impact of Warped Extra Dimensions on the Dipole Coefficients in
  $\boldsymbol{b\to s\gamma}$ Transitions

We calculate the electro- and chromomagnetic dipole coefficients
$C_{7\gamma,8g}$ and $\tilde C_{7\gamma,8g}$ in the context of the minimal
Randall-Sundrum (RS) model with a Higgs sector localized on the IR brane using
the five-dimensional (5D) approach, where the coefficients are expressed in
terms of integrals over 5D propagators. Since we keep the full dependence on
the Yukawa matrices, the integral expressions are formally valid to all orders
in $v^2/M_{\rm KK}^2$. In addition we relate our results to the expressions
obtained in the Kaluza-Klein (KK) decomposed theory and show the consistency in
both pictures analytically and numerically, which presents a non-trivial
cross-check. In Feynman-'t Hooft gauge, the dominant corrections from virtual
KK modes arise from the scalar parts of the $W^\pm$-boson penguin diagrams,
including the contributions from the scalar component of the 5D gauge-boson
field and from the charged Goldstone bosons in the Higgs sector. The size of
the KK corrections depends on the parameter $y_\ast$, which sets the upper
bound for the anarchic 5D Yukawa matrices. We find that for $y_\ast\gtrsim1$
the dominant KK corrections are proportional to $y_\ast^2$. We discuss the
phenomenological implications of our results for the branching ratio ${\rm
Br}(\bar B\to X_s\gamma)$, the time-dependent CP asymmetry $S_{K^*\gamma}$, the
direct CP asymmetry $A_{\rm CP}^{b\to s\gamma}$ and the CP asymmetry difference
$\Delta A_{\rm CP}^{b\to s\gamma}$. We can derive a lower bound on the first KK
gluon resonance of $3.8\,$TeV for $y_\ast=3$, requiring that at least $10\%$ of
the RS parameter space covers the experimental $2\sigma$ error margins. We
further discuss the branching ratio ${\rm Br}(\bar B\to X_sl^+l^-)$ and compare
our predictions for $C_{7\gamma,9,10}$ and $\tilde C_{7\gamma,9,10}$ with
phenomenological results derived from model-independent analyses.Comment: 44 pages plus appendix, 10 figures, added equations (58) and (61
Scalar triplet on a domain wall: an exact solution

We study a model with a real scalar Higgs field and a scalar triplet field
that allows existence of a topological defect -- a domain wall. The wall breaks
the global $O(3)$ symmetry of the model, which gives rise to non-Abelian
orientational degrees of freedom. We found an exact analytic solution that
describes a domain wall with a localized configuration of the triplet field on
it. This solution enables one to calculate contributions to the action from the
orientational and translational degrees of freedom of the triplet field. We
also study the linear stability of the domain wall with the triplet field
switched off. We obtain that degrees of freedom localized on the wall can
appear or do not appear depending on the parameters of the model.Comment: 14 pages, 4 figures; v2: typos corrected, references added, minor
  changes to match version published in JHE