pinecone/core-2020-05-10-deduplication huggingface dataset:
Analytical and numerical analysis of a rotational invariant D=2 harmonic
  oscillator in the light of different noncommutative phase-space
  configurations

In this work we have investigated some properties of classical phase-space
with symplectic structures consistent, at the classical level, with two
noncommutative (NC) algebras: the Doplicher-Fredenhagen-Roberts algebraic
relations and the NC approach which uses an extended Hilbert space with
rotational symmetry. This extended Hilbert space includes the operators
$\theta^{ij}$ and their conjugate momentum $\pi_{ij}$ operators. In this
scenario, the equations of motion for all extended phase-space coordinates with
their corresponding solutions were determined and a rotational invariant NC
Newton's second law was written. As an application, we treated a NC harmonic
oscillator constructed in this extended Hilbert space. We have showed precisely
that its solution is still periodic if and only if the ratio between the
frequencies of oscillation is a rational number. We investigated, analytically
and numerically, the solutions of this NC oscillator in a two-dimensional
phase-space. The result led us to conclude that noncommutativity induces a
stable perturbation into the commutative standard oscillator and that the
rotational symmetry is not broken. Besides, we have demonstrated through the
equations of motion that a zero momentum $\pi_{ij}$ originated a constant NC
parameter, namely, $\theta^{ij}=const.$, which changes the original variable
characteristic of $\theta^{ij}$ and reduces the phase-space of the system. This
result shows that the momentum $\pi_{ij}$ is relevant and cannot be neglected
when we have that $\theta^{ij}$ is a coordinate of the system.Comment: 18 pages. JHEP style. Corrections mad
Self-Completeness and the Generalized Uncertainty Principle

The generalized uncertainty principle discloses a self-complete
characteristic of gravity, namely the possibility of masking any curvature
singularity behind an event horizon as a result of matter compression at the
Planck scale. In this paper we extend the above reasoning in order to overcome
some current limitations to the framework, including the absence of a
consistent metric describing such Planck-scale black holes. We implement a
minimum-size black hole in terms of the extremal configuration of a neutral
non-rotating metric, which we derived by mimicking the effects of the
generalized uncertainty principle via a short scale modified version of
Einstein gravity. In such a way, we find a self-consistent scenario that
reconciles the self-complete character of gravity and the generalized
uncertainty principle.Comment: 20 pages, 6 figures, v2: additional references, version in press on
  JHE
Line defects and (framed) BPS quivers

The BPS spectrum of certain N=2 supersymmetric field theories can be
determined algebraically by studying the representation theory of BPS quivers.
We introduce methods based on BPS quivers to study line defects. The presence
of a line defect opens up a new BPS sector: framed BPS states can be bound to
the defect. The defect can be geometrically described in terms of laminations
on a curve. To a lamination we associate certain elements of the Leavitt path
algebra of the BPS quiver and use them to compute the framed BPS spectrum. We
also provide an alternative characterization of line defects by introducing
framed BPS quivers. Using the theory of (quantum) cluster algebras, we derive
an algorithm to compute the framed BPS spectra of new defects from known ones.
Line defects are generated from a framed BPS quiver by applying certain
sequences of mutation operations. Framed BPS quivers also behave nicely under a
set of "cut and join" rules, which can be used to study how N=2 systems with
defects couple to produce more complicated ones. We illustrate our formalism
with several examples.Comment: 80 pages, 16 figures; v2: references added, note added, minor
  corrections, final version to be published in JHE
Deconfinement in N=1 super Yang-Mills theory on R^3 x S^1 via
  dual-Coulomb gas and "affine" XY-model

We study finite-temperature N=1 SU(2) super Yang-Mills theory, compactified
on a spatial circle of size L with supersymmetric boundary conditions. In the
semiclassical small-L regime, a deconfinement transition occurs at T_c <<1/L.
The transition is due to a competition between non-perturbative topological
"molecules"---magnetic and neutral bion-instantons---and electrically charged
W-bosons and superpartners. Compared to deconfinement in non-supersymmetric
QCD(adj) arXiv:1112.6389, the novelty is the relevance of the light modulus
scalar field. It mediates interactions between neutral bions (and W-bosons),
serves as an order parameter for the Z_2^{L} center symmetry associated with
the non-thermal circle, and explicitly breaks the electric-magnetic
(Kramers-Wannier) duality enjoyed by non-supersymmetric QCD(adj) near T_c. We
show that deconfinement can be studied using an effective two-dimensional gas
of electric and magnetic charges with (dual) Coulomb and Aharonov-Bohm
interactions, or, equivalently, via an XY-spin model with a symmetry-breaking
perturbation, where each system couples to the scalar field. To study the
realization of the discrete R-symmetry and the Z_2^{beta} thermal and Z_2^{L}
non-thermal center symmetries, we perform Monte Carlo simulations of both
systems. The dual-Coulomb gas simulations are a novel way to analyze
deconfinement and provide a new venue to study the phase structure of a class
of two-dimensional condensed matter models that can be mapped into dual-Coulomb
gases. Our results indicate a continuous deconfinement transition, with Z_2^{L}
remaining unbroken at the transition. Thus, the SYM transition appears similar
to the one in SU(2) QCD(adj) arXiv:1112.6389 and is also likely to be
characterized by continuously varying critical exponents.Comment: 50 pages, 13 figure
Discrete gauge symmetries from (closed string) tachyon condensation

The study of discrete gauge symmetries in field theory and string theory is
often carried out by embedding them into continuous symmetries. Many symmetries
however do not seem to admit such embedding, for instance discrete isometries
given by large diffeomorphisms in compactifications. We show that in the
context of string theory even those symmetries can be embedded into continuous
ones. This requires extending the system to a supercritical string theory
configuration with extra dimensions, on which the continuous symmetry acts. The
extra dimensions are subsequently removed by closed string tachyon
condensation, which breaks the continuous symmetry but preserves a discrete
subgroup. The construction is explicit and the tachyon condensation can even be
followed quantitatively for lightlike tachyon profiles. The embedding of
discrete into continuous symmetries allows a realization of charged topological
defects as closed string tachyon solitons, in tantalizing reminiscence of the
construction of D-branes as open tachyon solitons.Comment: 32 pages + appendice
2d SCFTs from M2-branes

We consider the low-energy limit of the two-dimensional theory on k M2-branes
suspended between a straight M5-brane and a curved M5-brane. We argue that it
is described by an N=(2,2) supersymmetric gauge theory with no matter fields
but with a non-trivial twisted superpotential, and also by an N=(2,2)
supersymmetric Landau-Ginzburg model, such that the (twisted) superpotentials
are determined by the shape of the M5-branes. We find particular cases realize
Kazama-Suzuki models. Evidence is provided by the study of ground states,
chiral rings, BPS spectra and S^2 partition functions of the systems.Comment: 27 pages, 48 color figures; v2: several minor change
Hexagon Wilson Loop OPE and Harmonic Polylogarithms

A recent, integrability-based conjecture in the framework of the Wilson loop
OPE for N=4 SYM theory, predicts the leading OPE contribution for the hexagon
MHV remainder function and NMHV ratio function to all loops, in integral form.
We prove that these integrals evaluate to a particular basis of harmonic
polylogarithms, at any order in the weak coupling expansion. The proof
constitutes an algorithm for the direct computation of the integrals, which we
employ in order to obtain the full (N)MHV OPE contribution in question up to 6
loops, and certain parts of it up to 12 loops. We attach computer-readable
files with our results, as well as an algorithm implementation which may be
readily used to generate higher-loop corrections. The feasibility of obtaining
the explicit kinematical dependence of the first term in the OPE in principle
at arbitrary loop order, offers promise for the suitability of this approach as
a non-perturbative description of Wilson loops/scattering amplitudes.Comment: 34 pages, 4 figures, 7 ancillary files; v2: typos corrected,
  references update
Cosmic censorship in Lovelock theory

In analyzing maximally symmetric Lovelock black holes with non-planar horizon
topologies, many novel features have been observed. The existence of finite
radius singularities, a mass gap in the black hole spectrum and solutions
displaying multiple horizons are noteworthy examples. Naively, in all these
cases, the appearance of naked singularities seems unavoidable, leading to the
question of whether these theories are consistent gravity theories. We address
this question and show that whenever the cosmic censorship conjecture is
threaten, an instability generically shows up driving the system to a new
configuration with presumably no naked singularities. Also, the same kind of
instability shows up in the process of spherical black holes evaporation in
these theories, suggesting a new phase for their decay. We find circumstantial
evidence indicating that, contrary to many claims in the literature, the cosmic
censorship hypothesis holds in Lovelock theory.Comment: 25 pages, 6 figure
Partition function of beta-gamma system on orbifolds

Partition function of beta-gamma systems on the orbifolds C^2/Z_N and C^3/Z_M
x Z_N are obtained as the invariant part of that on the respective affine
spaces, by lifting the geometric action of the orbifold group to the fields.
Interpreting the sum over roots of unity as an elementary contour integration,
the partition function evaluates to an infinite series counting invariant
monomials composed of basic operators of the theory at each mass level.Comment: 14 pages; v2:corrected one typo, added reference
Twist-two operators and the BFKL regime - nonstandard solutions of the
  Baxter equation

The link between BFKL physics and twist-two operators involves an analytical
continuation in the spin of the operators away from the physical even integer
values. Typically this is done only after obtaining an analytical result for
integer spin through nested harmonic sums. In this paper we propose analyticity
conditions for the solution of Baxter equation which would work directly for
any value of complex spin and reproduce results from the analytical
continuation of harmonic sums. We carry out explicit contructions up to 2-loop
level. These nonstandard solutions of the Baxter equation have rather
surprising asymptotics. We hope that these analyticity conditions may be used
for incorporating them into the exact TBA/FiNLIE/QSC approaches valid at any
coupling.Comment: 22 pages, 1 figure, Mathematica notebook with numerical checks
  included in the source submissio
Physical factorisation scheme for PDFs for non-inclusive applications

We introduce the physical factorisation scheme, which is necessary to
describe observables which are `not completely inclusive'. We derive the
formulae for NLO DGLAP evolution in this scheme, and also for the `rotation' of
the conventional MSbar PDFs into the physical representation. Unlike, the MSbar
prescription, where, for example, the gluon PDF at NLO obtains an admixture of
the quark-singlet PDF, and vice-versa, the physical approach does not mix
parton PDFs of different types. That is, the physical approach retains the
precise quantum numbers of each PDF. The NLO corrections to DGLAP evolution in
the physical scheme are less than those in the MSbar case, indicating a better
convergence of the perturbative series
5d gauge theories on orbifolds and 4d 't Hooft line indices

We study indices for 5d gauge theories on S^1 \times S^4/Z_n. In the large
orbifold limit, n \rightarrow \infty, we find evidence that the indices become
4d indices in the presence of a 't Hooft line operator. The non-perturbative
part of the index poses some subtleties when being compared to the 4d monopole
bubbling which happens in the presence of 't Hooft line operators. We study
such monopole bubbling indices and find an interesting connection to the
Hilbert series of the moduli space of instantons on an auxiliary ALE space.Comment: 43 page
The mass spectrum of the Schwinger model with Matrix Product States

We show the feasibility of tensor network solutions for lattice gauge
theories in Hamiltonian formulation by applying matrix product states
algorithms to the Schwinger model with zero and non-vanishing fermion mass. We
introduce new techniques to compute excitations in a system with open boundary
conditions, and to identify the states corresponding to low momentum and
different quantum numbers in the continuum. For the ground state and both the
vector and scalar mass gaps in the massive case, the MPS technique attains
precisions comparable to the best results available from other techniques.Comment: updated numerical results; accepted versio
Tree-level Correlators of scalar and vector fields in AdS/CFT

Extending earlier results by Paulos, we discuss further the use of the
embedding formalism and Mellin transform in the calculation of tree-level
correlators of scalar and vector fields in AdS/CFT. We present an iterative
procedure that builds amplitudes by sewing together lower-point off-shell
diagrams. Both scalar and vector correlators are shown to be given in terms of
Mellin amplitudes. We apply the procedure to the explicit calculation of
three-, four- and five-point correlators.Comment: 21 page
Auxiliary Gauge Mediation: A New Route to Mini-Split Supersymmetry

The discovery of a standard-model-like Higgs at 126 GeV and the absence of
squark signals thus far at the LHC both point towards a mini-split spectrum for
supersymmetry. Within standard paradigms, it is non-trivial to realize a
mini-split spectrum with heavier sfermions but lighter gauginos while
simultaneously generating Higgs sector soft terms of the correct magnitude,
suggesting the need for new models of supersymmetry breaking and mediation. In
this paper, we present a new approach to mini-split model building based on
gauge mediation by ``auxiliary groups'', which are the anomaly-free continuous
symmetries of the standard model in the limit of vanishing Yukawa couplings. In
addition to the well-known flavor SU(3)_F and baryon-minus-lepton U(1)_{B-L}
groups, we find that an additional U(1)_H acting on the Higgs doublets alone
can be used to generate Higgs soft masses and B-terms necessary for a complete
model of mini-split. Auxiliary gauge mediation is a special case of Higgsed
gauge mediation, and we review the resulting two-loop scalar soft terms as well
as three-loop gaugino masses. Along the way, we present a complete two-loop
calculation of A-terms and B-terms in gauge mediation, which---contrary to a
common misconception---includes a non-zero contribution at the messenger
threshold which can be sizable in models with light gauginos. We present
several phenomenologically acceptable mini-split spectra arising from auxiliary
gauge mediation and highlight a complete minimal model which realizes the
required spectrum and Higgs sector soft terms with a single U(1)_X auxiliary
gauge symmetry. We discuss possible experimental consequences.Comment: 28 pages, 4 figures, 3 tables; v3: minor wording changes and
  reference added to acknowledge priority of previous B-term calculations.
  Conclusions unchanged. To be published in JHEP. v2: references added and
  typos correcte
Fast Scramblers And Ultrametric Black Hole Horizons

We propose that fast scrambling on finite-entropy stretched horizons can be
modeled by a diffusion process on an effective ultrametric geometry. A
scrambling time scaling logarithmically with the entropy is obtained when the
elementary transition rates saturate causality bounds on the stretched horizon.
The so-defined ultrametric diffusion becomes unstable in the infinite-entropy
limit. A formally regularized version can be shown to follow a particular case
of the Kohlrausch law.Comment: 14 pages, 2 figures. Two extra sections, one figure and references
  adde
On short interval expansion of R\'enyi entropy

R\'enyi entanglement entropy provides a new window to study the AdS/CFT
correspondence. In this paper we consider the short interval expansion of
R\'enyi entanglement entropy in two-dimensional conformal field theory. This
amounts to do the operator product expansion of the twist operators. We focus
on the vacuum Verma module and consider the quasiprimary operators constructed
from the stress tensors. After obtaining the expansion coefficients of the
twist operators to level 6 in vacuum Verma module, we compute the leading
contributions to the R\'enyi entropy, to order 6 in the short interval
expansion. In the case of one short interval on cylinder, we reproduce the
first several leading contributions to the R\'enyi entropy. In the case of two
short disjoint intervals with a small cross ratio $x$, we obtain not only the
classical and 1-loop quantum contributions to the R\'enyi entropy to order
$x^6$, both of which are in perfect match with the ones found in gravity, but
also the leading $1/c$ contributions, which corresponds to 2-loop corrections
in the bulk.Comment: V1, 23 pages, 5 figures; V2, published version, typos corrected,
  references adde
Critical points and number of master integrals

We consider the question about the number of master integrals for a multiloop
Feynman diagram. We show that, for a given set of denominators, this number is
totally determined by the critical points of the polynomials entering either of
the two representations: the parametric representation and the Baikov
representation. In particular, for the parametric representation the
corresponding polynomial is just the sum of Symanzik polynomials. The relevant
topological invariant is the sum of the Milnor numbers of the proper critical
points. We present a Mathematica package Mint to automatize the counting of the
master integrals.Comment: 16 pages, minor change
Constraining Light Dark Matter with Low-Energy e+e- Colliders

We investigate the power of low-energy, high-luminosity electron--positron
colliders to probe hidden sectors with a mass below ~10 GeV that couple to
Standard Model particles through a light mediator. Such sectors provide
well-motivated dark matter candidates, and can give rise to distinctive
mono-photon signals at B-factories and similar experiments. We use data from an
existing mono-photon search by BaBar to place new constraints on this class of
models, and give projections for the sensitivity of a similar search at a
future B-factory such as Belle II. We find that the sensitivity of such
searches are more powerful than searches at other collider or fixed-target
facilities for hidden-sector mediators and particles with masses between a few
hundred MeV and 10 GeV. Mediators produced on-shell and decaying invisibly to
hidden-sector particles such as dark matter can be probed particularly well.
Sensitivity to light dark matter produced through an off-shell mediator is more
limited, but may be improved with a better control of backgrounds, allowing
background estimation and a search for kinematic edges. We compare our results
to existing and future direct detection experiments and show that low-energy
colliders provide an indispensable and complementary avenue to search for light
dark matter. The implementation of a mono-photon trigger at Belle II would
provide an unparalleled window into such light hidden sectors.Comment: 16 pages, 10 figures; typos corrected and references adde
Holographic deconfinement transition in the presence of a magnetic field

We investigate the thermodynamics of the flavour sector of the Sakai-Sugimoto
model in the presence of a magnetic field. Renormalizing the euclidean
Dirac-Born-Infeld action in the antipodal limit, we find for the confined and
deconfined phases positive contributions to the pressures that grow with the
magnetic field. We also obtain positive magnetic susceptibilities indicating a
paramagnetic behaviour of quarks. Using these results we estimate a
\lambda^2/N_c correction to the deconfinement temperature that decreases as a
function of the magnetic field.Comment: V4 1+20 pages, 6 figures, references and one figure added. Version
  published in JHE
On Classifying the Divisor Involutions in Calabi-Yau Threefolds

In order to support the odd moduli in models of (type IIB) string
compactification, we classify the Calabi-Yau threefolds with h^{1,1}<=4 which
exhibit pairs of identical divisors, with different line-bundle charges,
mapping to each other under possible divisor exchange involutions. For this
purpose, the divisors of interest are identified as completely rigid surface,
Wilson surface, K3 surface and some other deformation surfaces. Subsequently,
various possible exchange involutions are examined under the symmetry of
Stanley-Reisner Ideal. In addition, we search for the Calabi-Yau theefolds
which contain a divisor with several disjoint components. Under certain
reflection involution, such spaces also have nontrivial odd components in
(1,1)-cohomology class. String compactifications on such Calabi-Yau
orientifolds with non-zero h^{1,1}_-(CY_3/\sigma) could be promising for
concrete model building in both particle physics and cosmology. In the spirit
of using such Calabi-Yau orientifolds in the context of LARGE volume scenario,
we also present some concrete examples of (strong/weak) swiss-cheese type
volume form.Comment: 33 pages, references added, with external Mathematica file, published
  in JHE
Fermion Portal Dark Matter

We study a class of simplified dark matter models in which one dark matter
particle couples with a mediator and a Standard Model fermion. In such models,
collider and direct detection searches probe complimentary regions of parameter
space. For Majorana dark matter, direct detection covers the region near
mediator-dark matter degeneracy, while colliders probe regions with a large
dark matter and mediator mass splitting. For Dirac and complex dark matter,
direct detection is effective for the entire region above the mass threshold,
but colliders provide a strong bound for dark matter lighter than a few GeV. We
also point out that dedicated searches for signatures with two jets or a
mono-jet not coming from initial state radiation, along missing transverse
energy can cover the remaining parameter space for thermal relic dark matter.Comment: 22 pages, 10 figures; corrections made on coannihilation parts,
  references added; corrections made on Majorana fermion direct detectio
Stability conditions for spatially modulated phases

We introduce a novel set of stability conditions for vacua with broken
Lorentz symmetry. The first class of conditions require that the energy be
minimized under small geometric deformations, which translates into requiring
the positivity of a "stiffness" four-tensor. The second class of conditions
requires that stress forces be restoring under small deformations. We then
apply these conditions to examples of recently-discovered spatially modulated
(or "striped") phases in holographic models of superconductors and high-density
QCD. For backreacted solutions we find that the pressure condition is
equivalent to thermodynamic stability. For probe solutions, however, these
conditions are in conflict with the minimization of the free energy. This
suggests that either the solutions are unstable or the definition of the free
energy in the probe approximation must be revised for these solutions.Comment: 28 pages, 6 figures, references adde