ShantanuT01/DACTYL-Pretraining huggingface dataset:
The $N \to \Delta$ weak vertex provides an important contribution to the one pion production in neutrino-nucleon and neutrino-nucleus scattering for $\pi N$ invariant masses below 1.4 GeV. Beyond its interest as a tool in neutrino detection and their background analyses, one pion production in neutrino-nucleon scattering is useful to test predictions based on the quark model and other internal symmetries of strong interactions. Here we try to establish a connection between two commonly used parametrizations of the weak $N \to \Delta$ vertex and form factors (FF) and we study their effects on the determination of the axial coupling $C_5^A(0)$, the common normalization of the axial FF, which is predicted to hold 1.2 by using the PCAC hypothesis. Predictions for the $\nu_{\mu} p \to \mu^- p\pi^+$ total cross sections within the two approaches, which include the resonant $\Delta^{++}$ and other background contributions in a coherent way, are compared to experimental data.
We study and compute an infinite family of Hurwitz spaces parameterizing covers of P_C branched at four points and deduce explicit regular S_n and A_n-extensions over Q(T) with totally real fibers.
Prompted by recent work of Adhikari, Cohen, Ayyagari and Strother "On chiral symmetry restoration at finite density in large-N_c QCD" (Phys. Rev. C 83, 065201 (2011)), we revisit the description of dense baryonic matter in terms of hyperspherical unit cells. We focus mainly on the interpretation of the unique energy, curvature and symmetry properties which enable such S^3 cells to describe full chiral restoration in Skyrme models and which markedly distinguish them from the flat and periodic unit cells of Skyrmion crystals. These key features clarify, in particular, why an S^3 cell interpretation as a crystal-cell model in which the specific cell geometry is without physical significance, as tentatively adopted by Adhikari et al., is insufficient. The ensuing criticism does therefore not apply to the usual interpretation of S^3 cells which we describe. We also suggest a few directions in which the latter interpretation may be developed further.
The quick and precise localization of GRBs by the Swift telescope allows the early evolution of the afterglow light curve to be captured by ground-based telescopes. With GROND measurements we can investigate the optical/near-infrared light curve of the afterglow of gamma-ray burst 080413B in the context of late rebrightening. Multi-wavelength follow-up observations were performed on the afterglow of GRB 080413B. X-ray emission was detected by the X-ray telescope onboard the Swift satellite and obtained from the public archive. Optical and near-infrared photometry was performed with the seven-channel imager GROND mounted at the MPG/ESO 2.2 m telescope and additionally with the REM telescope, both in La Silla, Chile. The light curve model was constructed using the obtained broad-band data. The broad-band light curve of the afterglow of GRB 080413B is well fitted with an on-axis two-component jet model. The narrow ultra-relativistic jet is responsible for the initial decay, while the rise of the moderately relativistic wider jet near its deceleration time is the cause of the rebrightening of the light curve. The later evolution of the optical/NIR light curve is then dominated by the wide component, the signature of which is almost negligible in the X-ray wavelengths. These components have opening angles of theta(narrow) ~1.7 degrees and theta(wide) ~9 degrees, and Lorentz factors of Gamma(narrow) >188 and Gamma(wide) ~18.5. We calculated the beaming-corrected energy release to be 7.9 x 10^48 erg.
The longitudinal resistivity $\rho_{xx}$ of two-dimensional electron gases formed in wells with two subbands displays ringlike structures when plotted in a density--magnetic-field diagram, due to the crossings of spin-split Landau levels (LLs) from distinct subbands. Using spin density functional theory and linear response, we investigate the shape and spin polarization of these structures as a function of temperature and magnetic-field tilt angle. We find that (i) some of the rings "break" at sufficiently low temperatures due to a quantum Hall ferromagnetic phase transition, thus exhibiting a high degree of spin polarization ($\sim 50 $%) within, consistent with the NMR data of Zhang \textit{et al.} [Phys. Rev. Lett. {\bf 98}, 246802 (2007)], and (ii) for increasing tilting angles the interplay between the anticrossings due to inter-LL couplings and the exchange-correlation (XC) effects leads to a collapse of the rings at some critical angle $\theta_c$, in agreement with the data of Guo \textit{et al.} [Phys. Rev. B {\bf 78}, 233305 (2008)].
We review two types of D-branes processes where open strings are created. In the first type, a closed string incident on a collection of D-branes is converted into a number of open strings running along them. For the case of threebranes we compare the leading absorption rate with that in semiclassical gravity, and find exact agreement. A supersymmetric non-renormalization theorem guarantees that this agreement survives all corrections in powers of the string coupling times the number of branes. The second type of process is creation of stretched open strings by crossing D-branes. We show that this is possible whenever a p-brane passes through an (8-p)-brane positioned orthogonally to it. The extra attractive force exerted by the stretched open string is crucial for finding that the net force cancels in this BPS system.
In this paper we discuss a class of double sums involving ratios of binomial coefficients. The sums are of the form \[ \sum_{j=0}^{n} \sum_{i=0}^j \frac{\binom{f_1(n)}{i}}{\binom{f_2(n)}{j}}\,c^{i-j}, \] where $f_1, f_2$ are functions of $n$. Such sums appear in the analyses of the Mabinogion urn and the Ehrenfest urn in probability. Using hypergeometric functions, we are able to simplify these sums, and in some cases express them in terms of the harmonic numbers.
Shifting by \pm 1 powers sums: p_i \to p_i \pm 1 induces a transformation on symmetric functions that we detail in the case of Hall-Littlewood polynomials. By iteration, this gives a description of these polynomials in terms of plane partitions, as well as some generating functions. We recover in particular an identity of Warnaar related to Rogers-Ramanujan identities.
We demonstrate that the thermodynamics of a perfect fluid describing baryonic matter can, in certain limits, lead to an equation of state similar to that of dark energy. We keep the cosmic fluid equation of state quite general by just demanding that the speed of sound is positive and less than the speed of light. In this framework, we discuss some propositions by looking at the asymptotic behavior of the cosmic fluid.
In this paper we study the equations governing the unsteady motion of an incompressible homogeneous generalized second grade fluid subject to periodic boundary conditions. We establish the existence of global-in-time strong solutions for shear thickening flows in the two and three dimensional case. We also prove uniqueness of such solution without any smallness condition on the initial data or restriction on the material moduli.
If mass and angular momentum were conserved in cooling flows associated with luminous, slowly rotating elliptical galaxies, the inflowing hot gas would spin up, resulting in disks of cold gas and X-ray images that are highly flattened along the equatorial plane out to several effective radii. Such X-ray flattening is not observed at the spatial resolution currently available to X-ray observations. Evidently mass and angular momentum are not in fact conserved. If cooling flows are depleted by localized radiative cooling at numerous sites distributed throughout the flows, then disks of cooled gas do not form and the X-ray images appear nearly circular. However, the distribution of young stars formed from the cooled gas is still somewhat flattened relative to the stellar light. X-ray images of galactic cooling flows can also be circularized by the turbulent diffusion of angular momentum away from the axis of rotation, but the effective viscosity of known processes -- stellar mass loss, supernovae, cooling site evolution, etc. -- is insufficient to appreciably circularize the X-ray images. Radial gradients in the interstellar iron abundance are unaffected by the expected level of interstellar turbulence since these gradients are continuously re-established by Type Ia supernovae.
Interaction-driven topological phase transitions in Dirac semimetals are investigated by means of large-scale quantum Monte Carlo (QMC) simulations. The interaction among Dirac fermions is introduced by coupling them to Ising spins that realize the quantum dynamics of the two-dimensional transverse field Ising model. The ground state phase diagram, in which the tuning parameters are the transverse field and the coupling between fermion and Ising spins, is determined. At weak and intermediate coupling, a second-order Ising quantum phase transition and a first-order topological phase transition between two topologically distinct Dirac semimetals are observed. Interestingly, at the latter, the Dirac points smear out to form nodal lines in the Brillouin zone, and collective bosonic fluctuations with SO(4) symmetry are strongly enhanced. At strong coupling, these two phase boundaries merge into a first-order transition.
We reach a thermodynamic interpretation of CODET model and its prediction to electrons density and temperature grounded on the physics of hydro magnetism in global equilibrium. The thermodynamic interpretation finds consistency with the model with a magneto-matter medium that is diamagnetic, in the context of ideal magnetohydrodynamics (MHD). It is further noticed that the CODET predicts a polytropic anomalous index for the electron gas of the Sun's corona. It is shown that this unusual characteristic is consistent with assuming that the low quiescent solar corona is a magneto-matter state which possesses an underlying structure that was earlier described to explain the 2-D adsorption process by a surface of a solid of molecules of a gas at a given temperature and pressure by Langmuir. In our case, it is assumed that we are in the presence of a 3-D similar coalescence process, i.e. a Langmuir amorphous lattice in thermodynamic equilibrium. In this way, constitutive properties of the medium magnetic permeability, the non-dispersive acoustic speed, the expected equilibration time for the 1.1 to 1.3$R_{\odot}$, and energy density are determined quantitatively for most of the quiescent corona in a near solar minimum that extends for several months from 2008 to 2009.
The Arecibo Ultra Deep Survey (AUDS) is a blind HI survey aimed at detecting galaxies beyond the local Universe in the 21-cm emission line of neutral hydrogen (HI). The Arecibo $L$-band Feed Array (ALFA) was used to image an area of 1.35~deg$^2$ to a redshift depth of 0.16, using a total on-source integration time of over 700 hours. The long integration time and small observation area makes it one of the most sensitive HI surveys, with a noise level of $\sim 75$~$\mu$Jy per 21.4~kHz (equivalent to 4.5~km~s$^{-1}$ at redshift $z=0$). We detect 247 galaxies in the survey, more than doubling the number already detected in AUDS60. The mass range of detected galaxies is $\log(M_{\rm HI}~[h_{70}^{-2}{\rm M}_\odot]) = 6.32 - 10.76$. A modified maximum likelihood method is employed to construct an HI mass function (HIMF). The best fitting Schechter parameters are: low-mass slope $\alpha = -1.37 \pm 0.05$, characteristic mass $\log(M^*~[h_{70}^{-2}{\rm M}_\odot]) = 10.15 \pm 0.09$, and density $\Phi_* = (2.41 \pm 0.57) \times 10^{-3} h_{70}^3$~Mpc$^{-3}$~dex$^{-1}$. The sample was divided into low and high redshift bins to investigate the evolution of the HIMF. No change in low-mass slope $\alpha$ was measured, but an increased characteristic mass $M^*$, was noted in the higher-redshift sample. Using Sloan Digital Sky Survey (SDSS) data to define relative galaxy number density, the dependence of the HIMF with environment was also investigated in the two AUDS regions. We find no significant variation in $\alpha$ or $M^*$. In the surveyed region, we measured a cosmic HI density $\Omega_{\rm HI} = (3.55 \pm 0.30) \times 10^{-4} h_{70}^{-1}$. There appears to be no evolutionary trend in $\Omega_{\rm HI}$ above $2\sigma$ significance between redshifts of 0 and 0.16.
The fundamental action of superon-graviton model(SGM) of Einstein-Hilbert type for space-time and matter is written down explicitly in terms of the fields of the graviton and superons by using the affine connection formalism and the spin connection formalism. Some characteristic structures including some hidden symmetries of the gravitational coupling of superons are manifested (in two dimensional space-time) with some details of the calculations. SGM cosmology is discussed briefly.
We investigate the Rabi oscillation of an atom placed inside a quantum cavity where each mirror is formed by a chain of atoms trapped near a one-dimensional waveguide. This proposal was studied previously with the use of Markov approximation, where the delay due to the finite travel time of light between the two cavity mirrors is neglected. We show that Rabi oscillation analogous to that obtained with high-finesse classical cavities is achieved only when this travel time is much larger than the time scale that characterizes the collective response of the atomic chain. Therefore, the delay must be taken into account and the dynamics of the problem is inherently non-Markovian. Parameters of interest such as the Rabi frequency and the cavity loss rate due to photon leakage through the mirrors are obtained.
A scalar field dark energy candidate could couple to ordinary matter and photons, enabling its detection in laboratory experiments. Here we study the quantum properties of the chameleon field, one such dark energy candidate, in an "afterglow" experiment designed to produce, trap, and detect chameleon particles. In particular, we investigate the possible fragmentation of a beam of chameleon particles into multiple particle states due to the highly non-linear interaction terms in the chameleon Lagrangian. Fragmentation could weaken the constraints of an afterglow experiment by reducing the energy of the regenerated photons, but this energy reduction also provides a unique signature which could be detected by a properly-designed experiment. We show that constraints from the CHASE experiment are essentially unaffected by fragmentation for $\phi^4$ and $1/\phi$ potentials, but are weakened for steeper potentials, and we discuss possible future afterglow experiments.
Local charge and spin currents are evaluated from the solutions of fully relativistic quantum mechanical scattering calculations for systems that include temperature-induced lattice and spin disorder as well as intrinsic alloy disorder. This makes it possible to determine material-specific spin transport parameters at finite temperatures. Illustrations are given for a number of important materials and parameters at 300 K. The spin-flip diffusion length $l_{\rm sf}$ of Pt is determined from the exponential decay of a spin current injected into a long length of thermally disordered Pt; we find $l_{\rm sf}^{\rm Pt}= 5.3\pm0.4 \,$nm. For the ferromagnetic substitutional disordered alloy Permalloy (Py), we inject currents that are fully polarized parallel and antiparallel to the magnetization and calculate $l_{\rm sf}$ from the exponential decay of their difference; we find $l_{\rm sf}^{\rm Py}= 2.8 \pm 0.1 \,$nm. The transport polarization $\beta$ is found from the asymptotic polarization of a charge current in a long length of Py to be $\beta = 0.75 \pm 0.01$. The spin Hall angle $\Theta_{\rm sH}$ is determined from the transverse spin current induced by the passage of a longitudinal charge current in thermally disordered Pt; our best estimate is $\Theta_{\rm sH}^{\rm Pt}=4.5 \pm 1 \%$ corresponding to the experimental room temperature bulk resistivity $\rho =10.8 \mu \Omega \,$cm.
We analyse the role played by system-environment correlations in the emergence of non-Markovian dynamics. By working within the framework developed in Breuer et al., Phys. Rev. Lett. 103, 210401 (2009), we unveil a fundamental connection between non-Markovian behaviour and dynamics of system-environment correlations. We derive an upper bound to the rate of change of the distinguishability between different states of the system that explicitly depends on the development and establishment of correlations between system and environment. We illustrate our results using a fully solvable spin-chain model, which allows us to gain insight on the mechanisms triggering non-Markovian evolution.
The widths of charge balance function in high energy hadron-hadron and relativistic heavy ion collisions are studied using the Monte Carlo generators PYTHIA and AMPT, respectively. The narrowing of balance function as the increase of multiplicity is found in both cases. The mean parton-freeze-out time of a heavy-ion-collision event is used as the characteristic hadronization time of the event. It turns out that for a fixed multiplicity interval the width of balance function is consistent with being independent of hadronization time.
Two hundred years ago, Andr\'e-Marie Amp\`ere discovered that electric loops in which currents of electrons are generated by a penetrating magnetic field can interact with each other. Here we show that Amp\`ere's observation can be transferred to the quantum realm of interactions between triangular plaquettes of spins on a lattice, where the electrical currents at the atomic scale are associated with a peculiar type of the orbital motion of electrons in response to the non-coplanarity of neighbouring spins playing the role of a magnetic field. The resulting topological orbital moment underlies the relation of the orbital dynamics with the topology of the spin structure. We demonstrate that the interactions of the topological orbital moments with each other and with the spins of the underlying lattice give rise to a new class of magnetic interactions $-$ topological chiral interactions $-$ which can dominate over the celebrated Dzyaloshinskii-Moriya interaction, thus opening a path for the realization of new classes of chiral magnetic materials with three-dimensional magnetization textures such as magnetic hopfions.
The kernel of the BFKL equation for non-zero momentum transfer is found at next-to-leading order. It is presented in various forms depending on the regularization of the infrared singularities in "virtual" and "real" parts of the kernel. The infrared safety of the total kernel is demonstrated and a form free from the singularities is suggested.
We present a new type of the Hamiltonian replica-exchange method, in which not temperatures but the van der Waals radius parameter is exchanged. By decreasing the van der Waals radii that control spatial sizes of atoms, this Hamiltonian replica-exchange method overcomes the steric restrictions and energy barriers. Furthermore, the simulation based on this method escapes from the local-minimum free-energy states and realizes effective sampling in the conformational space. We applied this method to an alanine dipeptide in aqueous solution and showed the effectiveness of the method by comparing the results with those obtained from the conventional canonical method.
We propose an algebraic and a geometric classification of euclidean isodual lattices of fixed rank. First, we prove that these lattices are distribued according to a finite number of algebraic types. Second, we show that they are parametrized by a finite number of symmetric spaces associated to the classical groups ${\bf SO}_0(p,q)$, ${\bf Sp}(2g,{\bf R})$ and ${\bf SU}(p,q)$. We obtain a complete discription of algebraic types and Gram matrices of isodual lattices up to rank 7. The maximal density problem is also discussed.
We consider a one-dimensional continuous time random walk with transition rates depending on an underlying autonomous simple symmetric exclusion process starting out of equilibrium. This model represents an example of a random walk in a slowly non-uniform mixing dynamic random environment. Under a proper space-time rescaling in which the exclusion is speeded up compared to the random walk, we prove a hydrodynamic limit theorem for the exclusion as seen by this walk and we derive an ODE describing the macroscopic evolution of the walk. The main difficulty is the proof of a replacement lemma for the exclusion as seen from the walk without explicit knowledge of its invariant measures. We further discuss how to obtain similar results for several variants of this model.
Models of minimal lepton flavor violation where the seesaw scale is higher than the relevant flavor scale predict that all lepton flavor violation is proportional to the charged lepton Yukawa matrix. If extra vector-like leptons are within the reach of the LHC, it will be possible to test the resulting predictions in ATLAS/CMS.
Here we prove that the minimal free resolution of a general space curve of large degree (e.g. a general space curve of degree d and genus g with d g+3, except for finitely many pairs (d,g)) is the expected one. A similar result holds even for general curves with special hyperplane section and, roughly, d g/2. The proof uses the so-called methode d'Horace.
A quasi-particle model has been employed to describe the $(2+1)$-flavor lattice QCD equation of state with physical quark masses. The interaction part of the equation of state has been mapped to the effective fugacities of otherwise non-interacting quasi-gluons and quasi-quarks. The mapping is found to be exact for the equation of state. The model leads to non-trivial dispersion relations for quasi-partons. The dispersion relations, effective quasi-particle number densities, and trace anomaly have been investigated employing the model.A Virial expansion for the EOS has further been obtained to investigate the role of interactions in quark-gluon plasma (QGP). Finally, Debye screening in QGP has been studied employing the model.
Let $G$ be a connected reductive group, and let $X$ be an affine $G$-spherical variety. We show that the classification of $\mathbb{G}_{a}$-actions on $X$ normalized by $G$ can be reduced to the description of quasi-affine homogeneous spaces under the action of a semi-direct product $\mathbb{G}_{a}\rtimes G$ with the following property. The induced $G$-action is spherical and the complement of the open orbit is either empty or a $G$-orbit of codimension one. These homogeneous spaces are parametrized by a subset ${\rm Rt}(X)$ of the character lattice $\mathbb{X}(G)$ of $G$, which we call the set of Demazure roots of $X$. We give a complete description of the set ${\rm Rt}(X)$ when $G$ is a semi-direct product of ${\rm SL}_{2}$ and an algebraic torus; we show particularly that ${\rm Rt}(X)$ can be obtained explicitly as the intersection of a finite union of polyhedra in $\mathbb{Q}\otimes_{\mathbb{Z}}\mathbb{X}(G)$ and a sublattice of $\mathbb{X}(G)$. We conjecture that ${\rm Rt}(X)$ can be described in a similar combinatorial way for an arbitrary affine spherical variety $X$.
Parsing human body into semantic regions is crucial to human-centric analysis. In this paper, we propose a segment-based parsing pipeline that explores human pose information, i.e. the joint location of a human model, which improves the part proposal, accelerates the inference and regularizes the parsing process at the same time. Specifically, we first generate part segment proposals with respect to human joints predicted by a deep model, then part- specific ranking models are trained for segment selection using both pose-based features and deep-learned part potential features. Finally, the best ensemble of the proposed part segments are inferred though an And-Or Graph.   We evaluate our approach on the popular Penn-Fudan pedestrian parsing dataset, and demonstrate the effectiveness of using the pose information for each stage of the parsing pipeline. Finally, we show that our approach yields superior part segmentation accuracy comparing to the state-of-the-art methods.