pinecone/core-2020-05-10-deduplication huggingface dataset:
On Field/String Theory Approach to Theta Dependence in Large N
  Yang-Mills Theory

The theta dependence of the vacuum energy in large N Yang-Mills theory has
been studied some time ago by Witten using a duality of large N gauge theories
with string theory compactified on a certain space-time. We show that within
the field theory context vacuum fluctuations of the topological charge give
rise to the vacuum energy consistent with the string theory computation.
Furthermore, we calculate 1/N suppressed corrections to the string theory
result. The reconciliation of the string and field theory approaches is based
on the fact that the gauge theory instantons carry zerobrane charge in the
corresponding D-brane construction of Yang-Mills theory. Given the formula for
the vacuum energy we study certain aspects of stability of the false vacua of
the model for different realizations of the initial conditions. The vacuum
structure appears to be different depending on whether N is infinite or,
alternatively, large but finite.Comment: 15 pages, RevTex; 2 references adde
Superstring Theory on AdS_2 x S^2 as a Coset Supermanifold

We quantize the superstring on the AdS_2 x S^2 background with Ramond-Ramond
flux using a PSU(1,1|2)/U(1) x U(1) sigma model with a WZ term. One-loop
conformal invariance of the model is guaranteed by a general mechanism which
holds for coset spaces G/H where G is Ricci-flat and H is the invariant locus
of a Z_4 automorphism of G. This mechanism gives conformal theories for the
PSU(1,1|2) x PSU(2|2)/SU(2) x SU(2) and PSU(2,2|4)/SO(4,1) x SO(5) coset
spaces, suggesting our results might be useful for quantizing the superstring
on AdS_3 x S^3 and AdS_5 x S^5 backgrounds.Comment: 34 pages, 4 figures, harvmac big mode ; typos corrected, clarified
  the choice of the real form
Reflection positivity and phase transitions in lattice spin models

Reflection positivity (RP) is a property of Gibbs measures exhibited by a
class of lattice spin systems that include the Ising, Potts and Heisenberg
models. The RP property is useful because of its two basic consequences:
infrared bound and chessboard estimates. These are one of basic (and rather
efficient) tools for proving phase transitions in many models of physical
interest. The notes presented hereby summarize the lectures on reflection
positivity and its consequences that the author delivered at the Prague Summer
School on Mathematical Statistical Mechanics in September 2006. The text
features both the classical material on the subject from the late 1970s as well
as some of the more recent developments.Comment: expanded and corrected version (content identical to that published
Scattering theory for the Schrodinger equation with repulsive potential

We consider the scattering theory for the Schrodinger equation with $-\Delta
-|x|^{\alpha}$ as a reference Hamiltonian, for $0< \alpha \leq 2$, in any space
dimension. We prove that when this Hamiltonian is perturbed by a potential, the
usual short range/long range condition is weakened: the limiting decay for the
potential depends on the value of $\alpha$, and is related to the growth of
classical trajectories in the unperturbed case. The existence of wave operators
and their asymptotic completeness are established thanks to Mourre estimates
relying on new conjugate operators. We construct the asymptotic velocity and
describe its spectrum. Some results are generalized to the case where
$-|x|^{\alpha}$ is replaced by a general second order polynomial.Comment: 47 pages, a4wide, no figur
Quantum Hexaspherical Observables for Electrons

A new quantum algebraic description of relativistic electrons, built on a
conformal dynamical symmetry (SO(4,2)), has recently been proposed to treat
localization in space-time. It is shown here that localization of an electron
may be represented by components of a SO(4,2) vector which are quantum
generalizations of the hexaspherical coordinates of classical projective
geometry. The shift of this vector under transformations to uniformly
accelerated frames is described by SO(4,2) rotations. Hexaspherical observables
also allow one to represent the quantum law of free fall under a form
explicitly compatible with the same dynamical symmetry.Comment: 9 page
λ-backbone colorings along pairwise disjoint stars and matchings.\ud

Given an integer λ≥2, a graph G=(V,E) and a spanning subgraph H of G (the backbone of G), a λ-backbone coloring of (G,H) is a proper vertex coloring V→{1,2,…} of G, in which the colors assigned to adjacent vertices in H differ by at least λ. We study the case where the backbone is either a collection of pairwise disjoint stars or a matching. We show that for a star backbone S of G the minimum number ℓ for which a λ-backbone coloring of (G,S) with colors in {1,…,ℓ} exists can roughly differ by a multiplicative factor of at most View the MathML source from the chromatic number χ(G). For the special case of matching backbones this factor is roughly View the MathML source. We also show that the computational complexity of the problem “Given a graph G with a star backbone S, and an integer ℓ, is there a λ-backbone coloring of (G,S) with colors in {1,…,ℓ}?” jumps from polynomially solvable to NP-complete between ℓ=λ+1 and ℓ=λ+2 (the case ℓ=λ+2 is even NP-complete for matchings). We finish the paper by discussing some open problems regarding planar graphs
Physically-based Dirac’s deltas functions in the static analysis of multi-cracked Euler-Bernoulli and Timoshenko beams

Dirac’s delta functions enable simple and effective representations of point loads and singularities in a variety of structural problems,\ud
leading very often to elegant and otherwise unworkable closed-form solutions. This is the case of cracked beams under static\ud
loads, whose theoretical and practical significance has attracted in recent years the interest of many researchers. Nevertheless,\ud
analytical formulations currently available for this problem are not completely satisfactory, either in terms of computational efficiency,\ud
when the continuity conditions must be enforced with auxiliary equations, or in terms of physical consistency, when the\ud
singularities in the beam’s flexural rigidity are represented with Dirac’s delta functions having a questionable negative sign. These\ud
considerations motivate the present study, which offers a novel and physically-based modelling of slender Euler-Bernoulli beams\ud
and short Timoshenko beams with any number and severity of cracks, conducing in both cases to exact closed-form solutions. For\ud
validation purposes in non-trivial examples, a standard finite element code is used, along with two nascent deltas (uniform and\ud
Gaussian density functions) to describe a smeared increase in the bending flexibility around the abscissa of the crack
Higher Derivative Corrections to Charged Fluids in 2n Dimensions

We study anomalous charged fluid in $2n$-dimensions ($n\geq 2$) up to
sub-leading derivative order. Only the effect of gauge anomaly is important at
this order. Using the Euclidean partition function formalism, we find the
constraints on different sub-leading order transport coefficients appearing in
parity-even and odd sectors of the fluid. We introduce a new mechanism to count
different fluid data at arbitrary derivative order. We show that only the
knowledge of independent scalar-data is sufficient to find the constraints. In
appendix we further extend this analysis to obtain fluid data at
sub-sub-leading order (where both gauge and gravitational anomaly contribute)
for parity-odd fluid.Comment: 43+1 pages, 8 tables; added explicit expressions of anomalous
  currents in section 3.1; fixed some typo
Pluto's atmosphere from stellar occultations in 2012 and 2013

We analyze two multi-chord stellar occultations by Pluto observed on July
18th, 2012 and May 4th, 2013, and monitored respectively from five and six
sites. They provide a total of fifteen light-curves, twelve of them being used
for a simultaneous fit that uses a unique temperature profile, assuming a clear
(no-haze) and pure N_2 atmosphere, but allowing for a possible pressure
variation between the two dates. We find a solution that fits satisfactorily
(i.e. within the noise level) all the twelve light-curves, providing
atmospheric constraints between ~1,190 km (pressure ~ 11 \mubar) and ~ 1,450 km
(pressure ~0.1 \mubar) from Pluto's center. Our main results are: (1) the
best-fitting temperature profile shows a stratosphere with strong positive
gradient between 1,190 km (at 36 K, 11 \mubar) and r = 1,215 km (6.0 \mubar),
where a temperature maximum of 110 K is reached; above it is a mesosphere with
negative thermal gradient of -0.2 K/km up to ~ 1,390 km (0.25 \mubar), where,
the mesosphere connects itself to a more isothermal upper branch around 81 K;
(2) the pressure shows a small (6 %) but significant increase (6-\sigma level)
between the two dates; (3) without troposphere, Pluto's radius is found to be
R_P = 1,190 +/- 5km. Allowing for a troposphere, R_P is constrained to lie
between 1,168 and 1,195 km; (4) the currently measured CO abundance is too
small to explain the mesospheric negative thermal gradient. Cooling by HCN is
possible, but only if this species is largely saturated; Alternative
explanations like zonal winds or vertical compositional variations of the
atmosphere are unable to explain the observed mesospheric trend.Comment: 41 pages, 13 figures, 4 table
Single bottom quark production in kT-factorisation

We present a study within the kT-factorisation scheme on single bottom quark
production at the LHC. In particular, we calculate the rapidity and transverse
momentum differential distributions for single bottom quark/anti-quark
production. In our setup, the unintegrated gluon density is obtained from the
NLx BFKL Green function whereas we included mass effects to the Lx heavy quark
jet vertex. We compare our results to the corresponding distributions predicted
by the usual collinear factorisation scheme. The latter were produced with
Pythia 8.1.Comment: 14 pages, 7 figures, 14 eps file
Intracellular zinc modulates cardiac ryanodine receptor-mediated calcium release

Aberrant Zn2+-homeostasis is a hallmark of certain cardiomyopathies associated with altered contractile force. In this study we addressed whether Zn2+ modulates cardiac ryanodine receptor gating and Ca2+-dynamics in isolated cardiomyocytes. We reveal that Zn2+ is a high affinity regulator of RyR2 displaying three modes of operation. Picomolar free Zn2+ concentrations potentiate RyR2 responses but channel activation is still dependent on the presence of cytosolic Ca2+. At concentrations of free Zn2+ >1 nM, Zn2+ is the main activating ligand and the dependency on Ca2+ is removed. Zn2+ is therefore a higher affinity activator of RyR2 than Ca2+. Millimolar levels of free Zn2+ were found to inhibit channel openings. In cardiomyocytes, consistent with our single-channel results, we show that Zn2+ modulates both the frequency and amplitude of Ca2+ waves in a concentration dependent manner and that physiological levels of Zn2+ elicit Ca2+-release in the absence of activating levels of cytosolic Ca2+. This highlights a new role for intracellular Zn2+ in shaping Ca2+-dynamics in cardiomyocytes through modulation of RyR2 gating.Publisher PDFPeer reviewe
Depletion of chondrocyte primary cilia reduces the compressive modulus of articular cartilage.

Primary cilia are slender, microtubule based structures found in the majority of cell types with one cilium per cell. In articular cartilage, primary cilia are required for chondrocyte mechanotransduction and the development of healthy tissue. Loss of primary cilia in Col2aCre;ift88(fl/fl) transgenic mice results in up-regulation of osteoarthritic (OA) markers and development of OA like cartilage with greater thickness and reduced mechanical stiffness. However no previous studies have examined whether loss of primary cilia influences the intrinsic mechanical properties of articular cartilage matrix in the form of the modulus or just the structural properties of the tissue. The present study describes a modified analytical model to derive the viscoelastic moduli based on previous experimental indentation data. Results show that the increased thickness of the articular cartilage in the Col2aCre;ift88(fl/fl) transgenic mice is associated with a reduction in both the instantaneous and equilibrium moduli at indentation strains of greater than 20%. This reveals that the loss of primary cilia causes a significant reduction in the mechanical properties of cartilage particularly in the deeper zones and possibly the underlying bone. This is consistent with histological analysis and confirms the importance of primary cilia in the development of a mechanically functional articular cartilage
Searches for heavy long-lived charged particles with the ATLAS detector in proton-proton collisions at √s = 8 Tev

Searches for heavy long-lived charged particles are performed using a data sample of 19.1 fb−1 from proton-proton collisions at a centre-of-mass energy of √s = 8 Tev collected by the ATLAS detector at the Large Hadron Collider. No excess is observed above the estimated background and limits are placed on the mass of long-lived particles in various supersymmetric models. Long-lived tau sleptons in models with gauge-mediated symmetry breaking are excluded up to masses between 440 and 385 GeV for tan β between 10 and 50, with a 290 GeV limit in the case where only direct tau slepton production is considered. In the context of simplified LeptoSUSY models, where sleptons are stable and have a mass of 300 GeV, squark and gluino masses are excluded up to a mass of 1500 and 1360 GeV, respectively. Directly produced charginos, in simplified models where they are nearly degenerate to the lightest neutralino, are excluded up to a mass of 620 GeV. R-hadrons, composites containing a gluino, bottom squark or top squark, are excluded up to a mass of 1270, 845 and 900 GeV, respectively, using the full detector; and up to a mass of 1260, 835 and 870 GeV using an approach disregarding information from the muon spectrometer
ATLAS search for new phenomena in dijet mass and angular distributions using pp collisions at sqrts=7 TeV

Mass and angular distributions of dijets produced in LHC proton-proton collisions at a centre-of-mass energy root s = 7TeV have been studied with the ATLAS detector using the full 2011 data set with an integrated luminosity of 4.8 fb(-1). Dijet masses up to similar to 4.0TeV have been probed. No resonance-like features have been observed in the dijet mass spectrum, and all angular distributions are consistent with the predictions of QCD. Exclusion limits on six hypotheses of new phenomena have been set at 95% CL in terms of mass or energy scale, as appropriate. These hypotheses include excited quarks below 2.83 TeV, colour octet scalars below 1.86TeV, heavy W bosons below 1.68 TeV, string resonances below 3.61 TeV, quantum black holes with six extra space-time dimensions for quantum gravity scales below 4.11 TeV, and quark contact interactions below a compositeness scale of 7.6 TeV in a destructive interference scenario
Electron-hopping modes in NiMn_(2)O_(4+δ) materials

The resistance versus temperature (R–T) characteristics of NiMn_(2)O_(4+δ) thermistors have been analyzed. In the literature, electron transport in manganate spinels is commonly described by a small-polaron model for nearest neighbor hopping, but variable range hopping (VRH) has not been considered so far. In this study differentiated R–T data were analyzed, allowing a clear distinction between different modes of hopping. In pressed pellets and thick screen printed films conduction was well described by a VRH model for a parabolic density of states, which was confirmed by scanning tunneling spectroscopy
The infrared structure of QCD amplitudes and in FDH and DRED

We consider variants of dimensional regularization, including the four-dimensional helicity scheme (FDH) and dimensional reduction (DRED), and present the gluon and quark form factors in the FDH scheme at next-to-next-to-leading order. We also discuss the generalization of the infrared factorization formula to FDH and DRED. This allows us to extract the cusp anomalous dimension as well as the quark and gluon anomalous dimensions at next-to-next-to-leading order in the FDH and DRED scheme, using MSbar and DRbar renormalization. To obtain these results we also present the renormalization procedure in these schemes
Search for standard model production of four top quarks in the lepton + jets channel in pp collisions at \( \sqrt{s}=8 \)TeV

A search is presented for standard model (SM) production of four top quarks (tt⎯⎯tt⎯⎯) in pp collisions in the lepton + jets channel. The data correspond to an integrated luminosity of 19.6 fb−1 recorded at a centre-of-mass energy of 8 TeV with the CMS detector at the CERN LHC. The expected cross section for SM tt⎯⎯tt⎯⎯ production is σSMtt⎯tt⎯≈1fb . A combination of kinematic reconstruction and multivariate techniques is used to distinguish between the small signal and large background. The data are consistent with expectations of the SM, and an upper limit of 32 fb is set at a 95% confidence level on the cross section for producing four top quarks in the SM, where a limit of 32 ± 17 fb is expected
Extrapolation and unitarity bounds for the $B \to \pi$ form factor

We address the problem of extrapolating the vector form factor $f_{B\pi}^+$, which is relevant to $B\to \pi\ell \nu_\ell$ decays, from the region of small to the region of large momentum transfer. As input, we use the QCD light-cone sum rule at small momentum transfer. We carry out a comprehensive Bayesian uncertainty analysis and obtain correlated uncertainties for the normalization and shape parameters of the form factor. The $z$-series parametrization for $f_{B\pi}^+$ is employed to extrapolate our results to large momentum transfer, and to compare with the lattice QCD results. To test the validity of our extrapolation we use the upper and lower bounds from the unitarity and positivity of the two-point correlator of heavy-light quark currents. This correlator is updated by including the NNLO perturbative term and the NLO correction to the quark condensate contribution. We demonstrate that an additional input including the form factor, its first and second derivative calculated at one value of momentum transfer from the light-cone sum rules, considerably improves the bounds. This only holds when the correlations between the form factor parameters are taken into account. We further combine our results with the latest experimental measurements of $B\to \pi \ell \nu_\ell$ by the BaBar and Belle collaborations, and obtain $|V_{ub}|=(3.32^{+0.26}_{-0.22}) \cdot 10^{-3}$ from a Bayesian analysis
Strangeness S = -2 baryon-baryon interactions using chiral effective field theory

We derive the leading order strangeness S = -2 baryon-baryon interactions in chiral effective field theory. The potential consists of contact terms without derivatives and of one-pseudoscalar-meson exchanges. The contact terms and the couplings of the pseudoscalar mesons to the baryons are related via SU(3)(f) symmetry to the S = -1 hyperon-nucleon channels. We show that the chiral effective field theory predictions with natural values for the low-energy constants agree with the experimental information in the S = -2 sector. (c) 2007 Elsevier B.V. All rights reserved
Nucleon electric dipole moments and the isovector parity- and time-reversal-odd pionânucleon coupling

The isovector time-reversal- and parity-violating pion–nucleon coupling View the MathML sourceg¯π(1) is uniquely sensitive to dimension-six interactions between right-handed light quarks and the Standard Model Higgs doublet that naturally arises in left-right symmetric models. Recent work has used the View the MathML sourceg¯π(1)-induced one-loop contribution to the neutron electric dipole moment dndn, together with the present experimental dndn bound, to constrain the CP-violating parameters of the left-right symmetric model. We show that this and related analyses are based on an earlier meson theory dndn computation that is not consistent with the power-counting appropriate for an effective field theory. We repeat the one-loop calculation using heavy baryon chiral perturbation theory and find that the resulting dndn sensitivity to View the MathML sourceg¯π(1) is suppressed, implying more relaxed constraints on the parameter space of the left-right symmetric model. Assuming no cancellations between this loop contribution and other contributions, such as the leading order EDM low-energy constant, the present limit on dndn implies View the MathML source|g¯π(1)|≲1.1×10−10
Higgs decay h → μτ with minimal flavor violation

We consider the tentative indication of flavor-violating Higgs boson decay h → μτ recently reported in the CMS experiment within the framework of minimal flavor violation. Specifically, we adopt the standard model extended with the seesaw mechanism involving right-handed neutrinos plus effective dimension-six operators satisfying the minimal flavor violation principle in the lepton sector. We find that it is possible to accommodate the CMS h → μτ signal interpretation provided that the right-handed neutrinos couple to the Higgs boson in some nontrivial way. We take into account empirical constraints from other lepton-flavor-violating processes and discuss how future searches for the μ → e γ decay and μ → e conversion in nuclei may further probe the lepton-flavor-violating Higgs couplings
Suicide rates and trends in Sao Paulo, Brazil, according to gender, age and demographic aspects: a joinpoint regression analysis

Objective: To evaluate suicide rates and trends in Sao Paulo by sex, age-strata, and methods. Methods: Data was collected from State registry from 1996 to 2009. Population was estimated using the National Census. We utilized joinpoint regression analysis to explore temporal trends. We also evaluated marital status, ethnicity, birthplace and methods for suicide. Results: In the period analyzed, 6,002 suicides were accrued with a rate of 4.6 per 100,000 (7.5 in men and 2.0 in women); the male-to-female ratio was around 3.7. Trends for men presented a significant decline of 5.3% per year from 1996 to 2002, and a significant increase of 2.5% from 2002 onwards. Women did not present significant changes. For men, the elderly (&gt; 65 years) had a significant reduction of 2.3% per year, while younger men (25-44 years) presented a significant increase of 8.6% from 2004 onwards. Women did not present significant trend changes according to age. Leading suicide methods were hanging and poisoning for men and women, respectively. Other analyses showed an increased suicide risk ratio for singles and foreigners. Conclusions: Specific epidemiological trends for suicide in the city of Sao Paulo that warrant further investigation were identified. High-risk groups - such as immigrants - could benefit from targeted strategies of suicide prevention