pinecone/core-2020-05-10-deduplication huggingface dataset:
Fluctuations around Periodic BPS-Density Waves in the Calogero Model

The collective field formulation of the Calogero model supports periodic
density waves. An important set of such density waves is a two-parameter family
of BPS solutions of the equations of motion of the collective field theory. One
of these parameters is essentially the average particle density, which
determines the period, while the other parameter determines the amplitude.
These BPS solutions are sometimes referred to as "small amplitude waves" since
they undulate around their mean density, but never vanish. We present complete
analysis of quadratic fluctuations around these BPS solutions. The
corresponding fluctuation hamiltonian (i.e., the stability operator) is
diagonalized in terms of bosonic creation and annihilation operators which
correspond to the complete orthogonal set of Bloch-Floquet eigenstates of a
related periodic Schr\"odinger hamiltonian, which we derive explicitly.
Remarkably, the fluctuation spectrum is independent of the parameter which
determines the density wave's amplitude. As a consequence, the sum over
zero-point energies of the field-theoretic fluctuation hamiltonian, and its
ensuing normal-ordering and regularization, are the same as in the case of
fluctuations around constant density background, namely, the ground state.
Thus, quadratic fluctuations do not shift the energy density tied with the
BPS-density waves studied here, compared to its ground state value. Finally, we
also make some brief remarks concerning fluctuations around non-BPS density
wavesComment: Latex, 34 pages. An appendix added. Version accepted for publication
  in the JHE
Skyrmions, instantons and holography

Some time ago, Atiyah and Manton observed that computing the holonomy of
Yang-Mills instantons yields good approximations to static Skyrmion solutions
of the Skyrme model. This paper provides an extension and explanation of this
result, by proving that instanton holonomies produce exact solutions of a BPS
Skyrme model, in which the Skyrme field is coupled to a tower of vector mesons.
Neglecting any (or indeed all) of the vector mesons breaks the scale invariance
and removes the BPS property of the Skyrmions. However, it is shown that a
truncation of the BPS Skyrme theory, in which only the first vector meson is
included, already moves the Skyrme model significantly closer to the BPS
system. A theory that is close to a BPS system is required to reproduce the
experimental data on binding energies of nuclei. A zero-mode quantization of
the Skyrmion is performed in the truncated BPS theory and the results are
compared to the physical properties of the nucleon. The approach is an analogue
in five-dimensional Minkowski spacetime of a recent holographic construction of
a Skyrme model by Sakai and Sugimoto, based on a string theory derivation of a
Yang-Mills-Chern-Simons theory in a curved five-dimensional spacetime.Comment: References added. Matches published versio
On the convergence of complex Langevin dynamics: the three-dimensional
  XY model at finite chemical potential

The three-dimensional XY model is studied at finite chemical potential using
complex Langevin dynamics. The validity of the approach is probed at small
chemical potential using imaginary chemical potential and continuity arguments,
and at larger chemical potential by comparison with the world line method.
While complex Langevin works for larger beta, we find that it fails for smaller
beta, in the region of the phase diagram corresponding to the disordered phase.
Diagnostic tests are developed to identify symptoms correlated with incorrect
convergence. We argue that the erroneous behaviour at smaller beta is not due
to the sign problem, but rather resembles dynamics observed in complex Langevin
simulations of simple models with complex noise.Comment: 21 pages, several eps figures; clarification and one figure added, to
  appear in JHE
Rational Terms in Theories with Matter

We study rational remainders associated with gluon amplitudes in gauge
theories coupled to matter in arbitrary representations. We find that these
terms depend on only a small number of invariants of the matter-representation
called indices. In particular, rational remainders can depend on the second and
fourth order indices only. Using this, we find an infinite class of
non-supersymmetric theories in which rational remainders vanish for gluon
amplitudes. This class includes all the "next-to-simplest" quantum field
theories of arXiv:0910.0930. This provides new examples of amplitudes in which
rational remainders vanish even though naive power counting would suggest their
presence.Comment: 10+4 pages. (v2) typos corrected, references adde
Hadronic production of squark-squark pairs: The electroweak
  contributions

We compute the electroweak (EW) contributions to squark--squark pair
production processes at the LHC within the framework of the Minimal
Supersymmetric Standard Model (MSSM). Both tree-level EW contributions, of
O(alpha_s alpha + alpha^2), and next-to-leading order (NLO) EW corrections, of
O(alpha_s^2 alpha), are calculated. Depending on the flavor and chirality of
the produced quarks, many interferences between EW-mediated and QCD-mediated
diagrams give non-zero contributions at tree-level and NLO. We discuss the
computational techniques and present an extensive numerical analysis for
inclusive squark--squark production as well as for subsets and single
processes. While the tree-level EW contributions to the integrated cross
sections can reach the 20% level, the NLO EW corrections typically lower the LO
prediction by a few percent.Comment: 36 pages, 18 figure
A Non Standard Supersymmetric Spectrum

Taking a bottom-up point of view and focussing on the lack of signals so far
in the Higgs and in the flavour sectors, we argue in favour of giving
consideration to supersymmetric extensions of the Standard Model where the
lightest Higgs boson has a mass between 200 and 300 GeV and the first two
generations of s-fermions are above 20 TeV. After examining the simplest
extensions of the Minimal Supersymmetric Standard Model that allow this in a
natural way, we summarize the main consequences of this pattern of masses at
the LHC and we analyze the consequences of a heavier than normal Higgs boson
for Dark Matter.Comment: 15 pages, 14 figures. v2: a subsection added on the constraint from
  colour conservation. v3: minor changes in Fig 3 due to numerical correction
Dirac Neutralinos and Electroweak Scalar Bosons of N=1/N=2 Hybrid
  Supersymmetry at Colliders

In the N=1 supersymmetric extension of the Standard Model, neutralinos
associated in supermultiplets with the neutral electroweak gauge and Higgs
bosons are, as well as gluinos, Majorana fermions. They can be paired with the
Majorana fermions of novel gaugino/scalar supermultiplets, as suggested by
extended N=2 supersymmetry, to Dirac particles. Matter fields are not extended
beyond the standard N=1 supermultiplets in N=1/N=2 hybrid supersymmetry to
preserve the chiral character of the theory. Complementing earlier analyses in
the color sector, central elements of such an electroweak scenario are analyzed
in the present study. The decay properties of the Dirac fermions and of the
scalar bosons are worked out, and the single and pair production channels of
the new particles are described for proton collisions at the LHC, and
electron/positron and photon-photon collisions at linear colliders. Special
attention is paid to modifications of the Higgs sector, identified with an N=2
hypermultiplet, by the mixing with the novel electroweak scalar sector.Comment: 33 pp. + 9 pp. appendix; few typos corrected, version to appear in
  JHE
Constraints on Automorphic Forms of Higher Derivative Terms from
  Compactification

By dimensionally reducing the higher derivative corrections of
ten-dimensional IIB theory on a torus we deduce constraints on the E_{n+1}
automorphic forms that occur in d=10-n dimensions. In particular we argue that
these automorphic forms involve the representation of E_{n+1} with fundamental
weight \lambda^{n+1}, which is also the representation to which the string
charges in d dimensions belong. We also consider a similar calculation for the
reduction of higher derivative terms in eleven-dimensional M-theory.Comment: Minor corrections, to appear in JHE
Combining subjet algorithms to enhance ZH detection at the LHC

The signal for a highly boosted heavy resonance competing against a
background of light parton jets at the LHC can be enhanced by analyzing subjets
in the "fat" jet that possibly contains the heavy resonance. Three methods for
doing this are known as filtering, pruning, and trimming. We study the
possibility of combining these methods using a relative likelihood approach. We
find that, because the methods are not the same, one achieves an enhanced
statistical power by combining them. We illustrate the possibilities first with
a simple problem of combining trimming and pruning to enhance the signal for
finding a boosted top quark. We then study the more difficult problem of
disentangling from the background the signal for the production of a Higgs
boson in association with a Z-boson. For this problem, we combine filtering,
trimming, and pruning.Comment: 19 pages with eight figures; v. 2 with some revisions for clarity to
  make the arXiv version close to the JHEP versio
Large-N volume independence in conformal and confining gauge theories

Consequences of large $N$ volume independence are examined in conformal and
confining gauge theories. In the large $N$ limit, gauge theories compactified
on $\R^{d-k} \times (S^1)^k$ are independent of the $S^1$ radii, provided the
theory has unbroken center symmetry. In particular, this implies that a large
$N$ gauge theory which, on $\R^d$, flows to an IR fixed point, retains the
infinite correlation length and other scale invariant properties of the
decompactified theory even when compactified on $\R^{d-k} \times (S^1)^k$. In
other words, finite volume effects are $1/N$ suppressed. In lattice
formulations of vector-like theories, this implies that numerical studies to
determine the boundary between confined and conformal phases may be performed
on one-site lattice models. In $N=4$ supersymmetric Yang-Mills theory, the
center symmetry realization is a matter of choice: the theory on
$\R^{4-k}\times (S^1)^k$ has a moduli space which contains points with all
possible realizations of center symmetry. Large $N$ QCD with massive adjoint
fermions and one or two compactified dimensions has a rich phase structure with
an infinite number of phase transitions coalescing in the zero radius limit.Comment: 24 pages, added re
Spontaneous fragmentation of topological black holes

We study the metastability of Anti-de Sitter topological black holes with
compact hyperbolic horizons. We focus on the five-dimensional case, an AdS/CFT
dual to thermal states in the maximally supersymmetric large-N Yang-Mills
theory, quantized on a three-dimensional compact hyperboloid. We estimate the
various rates for quantum-statistical D3-brane emission, using WKB methods in
the probe-brane approximation, including thermal tunneling and Schwinger pair
production. The topological black holes are found to be metastable at high
temperature. At low temperatures, D-branes are emitted without exponential
suppression in superradiant modes, producing an instability in qualitative
agreement with expectations from weakly-coupled gauge dynamics.Comment: 19 pages, 4 figure
Light-like polygonal Wilson loops in 3d Chern-Simons and ABJM theory

We study light-like polygonal Wilson loops in three-dimensional Chern-Simons
and ABJM theory to two-loop order. For both theories we demonstrate that the
one-loop contribution to these correlators cancels. For pure Chern-Simons, we
find that specific UV divergences arise from diagrams involving two cusps,
implying the loss of finiteness and topological invariance at two-loop order.
Studying those UV divergences we derive anomalous conformal Ward identities for
n-cusped Wilson loops which restrict the finite part of the latter to
conformally invariant functions. We also compute the four-cusp Wilson loop in
ABJM theory to two-loop order and find that the result is remarkably similar to
that of the corresponding Wilson loop in N=4 SYM. Finally, we speculate about
the existence of a Wilson loop/scattering amplitude relation in ABJM theory.Comment: 37 pages, many figures; v2: references added, minor changes; v3:
  references added, sign error fixed and note adde
Emergent Gauge Fields in Holographic Superconductors

Holographic superconductors have been studied so far in the absence of
dynamical electromagnetic fields, namely in the limit in which they coincide
with holographic superfluids. It is possible, however, to introduce dynamical
gauge fields if a Neumann-type boundary condition is imposed on the
AdS-boundary. In 3+1 dimensions, the dual theory is a 2+1 dimensional CFT whose
spectrum contains a massless gauge field, signaling the emergence of a gauge
symmetry. We study the impact of a dynamical gauge field in vortex
configurations where it is known to significantly affect the energetics and
phase transitions. We calculate the critical magnetic fields H_c1 and H_c2,
obtaining that holographic superconductors are of Type II (H_c1 < H_c2). We
extend the study to 4+1 dimensions where the gauge field does not appear as an
emergent phenomena, but can be introduced, by a proper renormalization, as an
external dynamical field. We also compare our predictions with those arising
from a Ginzburg-Landau theory and identify the generic properties of Abrikosov
vortices in holographic models.Comment: 19 pages, 14 figures, few comments added, version published in JHE
Hidden Conformal Symmetry of the Reissner-Nordstr{\o}m Black Holes

Motivated by recent progresses in the holographic descriptions of the Kerr
and Reissner-Nordstr{\o}m (RN) black holes, we explore the hidden conformal
symmetry of nonextremal uplifted 5D RN black hole by studying the near horizon
wave equation of a massless scalar field propagating in this background.
Similar to the Kerr black hole case, this hidden symmetry is broken by the
periodicity of the associated angle coordinate in the background geometry, but
the results somehow testify the dual CFT description of the nonextremal RN
black holes. The duality is further supported by matching of the entropies and
absorption cross sections calculated from both CFT and gravity sides.Comment: 14 pages, no figur
Holographic studies of quasi-topological gravity

Quasi-topological gravity is a new gravitational theory including
curvature-cubed interactions and for which exact black hole solutions were
constructed. In a holographic framework, classical quasi-topological gravity
can be thought to be dual to the large $N_c$ limit of some non-supersymmetric
but conformal gauge theory. We establish various elements of the AdS/CFT
dictionary for this duality. This allows us to infer physical constraints on
the couplings in the gravitational theory. Further we use holography to
investigate hydrodynamic aspects of the dual gauge theory. In particular, we
find that the minimum value of the shear-viscosity-to-entropy-density ratio for
this model is $\eta/s \simeq 0.4140/(4\pi)$.Comment: 45 pages, 6 figures. v2: References adde
Flavor Structure in F-theory Compactifications

F-theory is one of frameworks in string theory where supersymmetric grand
unification is accommodated, and all the Yukawa couplings and Majorana masses
of right-handed neutrinos are generated. Yukawa couplings of charged fermions
are generated at codimension-3 singularities, and a contribution from a given
singularity point is known to be approximately rank 1. Thus, the approximate
rank of Yukawa matrices in low-energy effective theory of generic F-theory
compactifications are minimum of either the number of generations N_gen = 3 or
the number of singularity points of certain types. If there is a geometry with
only one E_6 type point and one D_6 type point over the entire 7-brane for
SU(5) gauge fields, F-theory compactified on such a geometry would reproduce
approximately rank-1 Yukawa matrices in the real world. We found, however, that
there is no such geometry. Thus, it is a problem how to generate hierarchical
Yukawa eigenvalues in F-theory compactifications. A solution in the literature
so far is to take an appropriate factorization limit. In this article, we
propose an alternative solution to the hierarchical structure problem (which
requires to tune some parameters) by studying how zero mode wavefunctions
depend on complex structure moduli. In this solution, the N_gen x N_gen CKM
matrix is predicted to have only N_gen entries of order unity without an extra
tuning of parameters, and the lepton flavor anarchy is predicted for the lepton
mixing matrix. We also obtained a precise description of zero mode
wavefunctions near the E_6 type singularity points, where the up-type Yukawa
couplings are generated.Comment: 148 page
Noncommutativity relations in type IIB theory and their supersymmetry

In the present paper we investigate noncommutativity of $D9$ and $D5$-brane
world-volumes embedded in space-time of type IIB superstring theory. Boundary
conditions, which preserve half of the initial supersymmetry, are treated as
canonical constraints. Solving the constraints we obtain original coordinates
in terms of the effective coordinates and momenta. Presence of momenta induces
noncommutativity of string endpoints. We show that noncommutativity relations
are connected by N=1 supersymmetry transformations and noncommutativity
parameters are components of N=1 supermultiplet
Fermionic vacuum polarization by a cosmic string in de Sitter spacetime

We investigate the fermionic condensate and the vacuum expectation value of
the energy-momentum tensor for a massive spinor field in the geometry of a
straight cosmic string on background of de Sitter spacetime. By using the
Abel-Plana summation formula, we explicitly extract form the expectation values
the contribution associated with purely de Sitter space, remaining the
expectation values induced by the cosmic string. The latter presents
information about de Sitter gravity as well. Because the investigation of the
fermionic quantum fluctuations in de Sitter space have been investigated in
literature, here we are mainly interested in the cosmic string-induced
contributions. For a massless field, the fermionic condensate vanishes and the
presence of the string does not break chiral symmetry of the massless theory.
Unlike to the case of a scalar field, for a massive fermionic field the vacuum
expectation value of the energy-momentum tensor is diagonal and the axial and
radial stresses are equal to the energy density. At large distances from the
string the behavior of the string-induced parts in the vacuum densities is
damping oscillatory with the amplitude decaying as the inverse fourth power of
the distance. This is in contrast to the case of flat spacetime, in which the
string-induced vacuum densities for a massive field decay exponentially with
distance from the string. In the limit of the large curvature radius of de
Sitter space we recover the results for a cosmic string in flat spacetime.Comment: 25 pages, 3 figure
Strong coupling, discrete symmetry and flavour

We show how two principles - strong coupling and discrete symmetry - can work
together to generate the flavour structure of the Standard Model. We propose
that in the UV the full theory has a discrete flavour symmetry, typically only
associated with tribimaximal mixing in the neutrino sector. Hierarchies in the
particle masses and mixing matrices then emerge from multiple strongly coupled
sectors that break this symmetry. This allows for a realistic flavour
structure, even in models built around an underlying grand unified theory. We
use two different techniques to understand the strongly coupled physics:
confinement in N=1 supersymmetry and the AdS/CFT correspondence. Both
approaches yield equivalent results and can be represented in a clear,
graphical way where the flavour symmetry is realised geometrically.Comment: 31 pages, 5 figures, updated references and figure
Nonlinear Hydrodynamics from Flow of Retarded Green's Function

We study the radial flow of retarded Green's function of energy-momentum
tensor and $R$-current of dual gauge theory in presence of generic higher
derivative terms in bulk Lagrangian. These are first order non-linear Riccati
equations. We solve these flow equations analytically and obtain second order
transport coefficients of boundary plasma. This way of computing transport
coefficients has an advantage over usual Kubo approach. The non-linear equation
turns out to be a linear first order equation when we study the Green's
function perturbatively in momentum. We consider several examples including
$Weyl^4$ term and generic four derivative terms in bulk. We also study the flow
equations for $R$-charged black holes and obtain exact expressions for second
order transport coefficients for dual plasma in presence of arbitrary chemical
potentials. Finally we obtain higher derivative corrections to second order
transport coefficients of boundary theory dual to five dimensional gauge
supergravity.Comment: Version 2, reference added, typos correcte
Quantum gravity effects on statistics and compact star configurations

The thermodynamics of classical and quantum ideal gases based on the
Generalized uncertainty principle (GUP) are investigated. At low temperatures,
we calculate corrections to the energy and entropy. The equations of state
receive small modifications. We study a system comprised of a zero temperature
ultra-relativistic Fermi gas. It turns out that at low Fermi energy
$\varepsilon_F$, the degenerate pressure and energy are lifted. The
Chandrasekhar limit receives a small positive correction. We discuss the
applications on configurations of compact stars. As $\varepsilon_F$ increases,
the radius, total number of fermions and mass first reach their nonvanishing
minima and then diverge. Beyond a critical Fermi energy, the radius of a
compact star becomes smaller than the Schwarzschild one. The stability of the
configurations is also addressed. We find that beyond another critical value of
the Fermi energy, the configurations are stable. At large radius, the increment
of the degenerate pressure is accelerated at a rate proportional to the radius.Comment: V2. discussions on the stability of star configurations added, 17
  pages, 2 figures, typos corrected, version to appear in JHE
On metastable vacua in perturbed N=2 theories

We study supersymmetry breaking in metastable vacua on the Coulomb branch of
perturbed N=2 gauge theories, with gauge group SU(2) and different matter
content (N_f=0,2,4). The theory is deformed with a superpotential which is a
cubic polynomial in u=Tr \Phi ^2, where \Phi is the adjoint superfield. The
allowed region of the perturbation parameters in this N=1 theory is plotted as
a function of the moduli space coordinate. In the asymptotically free cases a
significant fine-tuning in the perturbation parameters is needed to achieve
metastable vacua in the weakly coupled region of the moduli space; a lower
degree of fine-tuning is required in the strongly coupled regime. In the
conformal case (N_f=4 fundamentals) we find that also an explicit mass for the
hypermultiplets must be introduced in order to generate metastable vacua. In
the case of N_f=2 fundamentals it is possible to achieve a metastable vacuum
also in the neighborhood of the Argyres-Douglas fixed point (even if a large
degree of fine-tuning is needed in this limit). Direct gauge mediation is
discussed; gaugino masses of the same order of the SUSY-breaking can be
obtained.Comment: 27 pages, 16 figures; v2: some typos correcte