ShantanuT01/DACTYL-Pretraining huggingface dataset:
The basic concepts of a generalized relativistic density functional approach to the equation of state of dense matter are presented. The model is an extension of relativistic mean-field models with density-dependent couplings. It includes explicit cluster degrees of freedom. The formation and dissolution of nuclei is described with the help of mass shifts. The model can be adapted to the description of finite nuclei in order to study the effect of $\alpha$-particle correlations at the nuclear surface on the neutron skin thickness of heavy nuclei. Further extensions of the model to include quark degrees of freedom or an energy dependence of the nucleon self-energies are outlined.
We introduce and we study a class of odd dimensional compact complex manifolds whose Hodge structure in middle dimension looks like that of a Calabi-Yau threefold. We construct several series of interesting examples from rational homogeneous spaces with special properties.
While in the lowest Landau level the electron-electron interaction leads to the formation of the Wigner crystal, in higher Landau levels a solid phase with multiple electrons in a lattice site of crystal was predicted, which was called the bubble phase. Reentrant integer quantum Hall states are believed to be the insulating bubble phase pinned by disorder. We carry out nonlinear transport measurements on the reentrant states and study the de-pinning of the bubble phase, which is complementary to previous microwave measurements and provides unique information. In this study, conductivity is directly measured with Corbino geometry. Based on the threshold electric field of de-pinning, a phase diagram of the reentrant state is mapped. We discuss an interaction-driven topological phase transition between the integer quantum Hall state and the reentrant integer quantum Hall state.
Next-generation optical imaging surveys will revolutionise the observations of weak gravitational lensing by galaxy clusters and provide stringent constraints on growth of structure and cosmic acceleration. In these experiments, accurate modelling of covariance matrices of cluster weak lensing plays the key role in obtaining robust measurements of the mean mass of clusters and cosmological parameters. We use a combination of analytical calculations and high-resolution N-body simulations to derive accurate covariance matrices that span from the virial regime to linear scales of the cluster-matter cross-correlation. We validate this calculation using a public ray-tracing lensing simulation and provide a software package for calculating covariance matrices for a wide range of cluster and source sample choices. We discuss the relative importance of shape noise and density fluctuations, the impact of radial bin size, and the impact of off-diagonal elements. For a weak lensing source density 10 per square arcmin, shape noise typically dominates the variance on comoving scales less than 5 Mpc/h. However, for 60 per square arcmin, potentially achievable with future weak lensing experiments, density fluctuations typically dominate the variance at scales greater than 1 Mpc/h and remain comparable to shape noise on smaller scales.
We prove that every odd number $N$ greater than 1 can be expressed as the sum of at most five primes, improving the result of Ramar\'e that every even natural number can be expressed as the sum of at most six primes. We follow the circle method of Hardy-Littlewood and Vinogradov, together with Vaughan's identity; our additional techniques, which may be of interest for other Goldbach-type problems, include the use of smoothed exponential sums and optimisation of the Vaughan identity parameters to save or reduce some logarithmic losses, the use of multiple scales following some ideas of Bourgain, and the use of Montgomery's uncertainty principle and the large sieve to improve the $L^2$ estimates on major arcs. Our argument relies on some previous numerical work, namely the verification of Richstein of the even Goldbach conjecture up to $4 \times 10^{14}$, and the verification of van de Lune and (independently) of Wedeniwski of the Riemann hypothesis up to height $3.29 \times 10^9$.
In the large extra dimensional braneworld inflation, Friedmann equation is modified to include a quadratic term in energy density with an additional parameter $\lambda$ called brane tension in addition to the usual linear term. The high energy brane corrections modify the slow-roll parameters and affect the behaviour of inflation. We analyse the superconformal inflation for E-models and find that there exist $\alpha$-attractors in brane inflation. The predictions for the scalar spectral index $n_s$ and the tensor-to-scalar ratio $r$ are computed numerically, and approximate analytic formulas in the high energy limit have been given for the observable $n_s$ and $r$. The constraints on the model parameters are obtained by using Planck 2018 and BICEP2 observational data.
Cohen and Lenstra detailed a heuristic for the distribution of odd p-class groups for imaginary quadratic fields. One such formulation of this distribution is that the expected number of surjections from the class group of an imaginary quadratic field k to a fixed odd abelian group is 1. Class field theory tells us that the class group is also the Galois group of the Hilbert class field, the maximal unramified abelian extension of k, so we could equivalently say the expected number of unramified G-extensions of k is 1/#Aut(G) for a fixed abelian group G. We generalize this to asking for the expected number of unramified G-extensions Galois over $\mathbb{Q}$ for a fixed finite group G, with no restrictions placed on G. We review cases where the answer is known or conjectured by Boston-Wood, Boston-Bush-Hajir, and Bhargava, then answer this question in several new cases. In particular, we show when the expected number is zero and give a nontrivial family of groups realizing this. Additionally, we prove the expected number for the quaternion group $Q_8$ and dihedral group $D_4$ of order 8 is infinite. Lastly, we discuss the special case of groups generated by elements of order 2 and give an argument for an infinite expected number based on Malle's conjecture.
This Letter is to investigate the physics of a newly discovered phenomenon -- contracting flare loops in the early phase of solar flares. In classical flare models, which were constructed based on the phenomenon of expansion of flare loops, an energy releasing site is put above flare loops. These models can predict that there is a vertical temperature gradient in the top of flare loops due to heat conduction and cooling effects. Therefore, the centroid of an X-ray looptop source at higher energy bands will be higher in altitude, for which we can define as normal temperature distribution. With observations made by {\it RHESSI}, we analyzed 10 M- or X-class flares (9 limb flares). For all these flares, the movement of looptop sources shows an obvious U-shaped trajectory, which we take as the signature of contraction-to-expansion of flare loops. We find that, for all these flares, normal temperature distribution does exist, but only along the path of expansion. The temperature distribution along the path of contraction is abnormal, showing no spatial order at all. The result suggests that magnetic reconnection processes in the contraction and expansion phases of these solar flares are different.
We consider the effects of anomalous magnetic dipole moments of vector mesons in the decay distribution of photons emitted in two-pseudoscalar decays of charged vector mesons. By choosing a kinematical configuration appropriate to isolate these effects from model-dependent and dominant bremsstrahlung contributions, we show that this method can provide a valid alternative for a measurement of the unknown magnetic dipole moments of charged vector mesons.
The black hole candidate MAXI J1535-571 is a recently discovered X-ray transient. We report on the monitoring observations of Swift Gamma-Ray Burst Mission during outburst. The source transits from the hard state to the intermediate state, and reaches the soft state; near the end of the outburst, it returns to the hard state passing through the low intermediate state, following a typical Q-shaped loop in the hardness-intensity diagram. During the high intermediate state, detailed spectral analyses using a multi-temperature disk model reveal that the disk luminosity is flatter than the inner disk temperature to the fourth power, and the disk temperature profile varies as the disk radius raised to the power of -0.5, consistent with the behavior of a slim disk, implying that the disk structure has been modified due to the high luminosity of ~ 10^{39} erg/s. Meanwhile, the column density increases with the Eddington ratio, suggesting that the outflow matters are driven by radiation pressure due to the high accretion rate.
We provide a uniform upper bound on the minimal drift so that the one-per-site frog model on a $d$-ary tree is recurrent. To do this, we introduce a subprocess that couples across trees with different degrees. Finding couplings for frog models on nested sequences of graphs is known to be difficult. The upper bound comes from combining the coupling with a new, simpler proof that the frog model on a binary tree is recurrent when the drift is sufficiently strong. Additionally, we describe a coupling between frog models on trees for which the degree of the smaller tree divides that of the larger one. This implies that the critical drift has a limit as $d$ tends to infinity along certain subsequences.
The Local Group (LG) is an environment accessible to detailed studies of galaxy formation, providing a complement to the early universe. In particular, spectroscopy of resolved stellar populations in the LG provides kinematical and chemical information for individual stars that can be used to infer the history of $L_\star$ galaxies like the Milky Way (MW) and Andromeda (M31). The Gaia revolution in the MW has enabled comprehensive observational studies of the MW's formation history. The exquisite detail in which the MW has been studied is currently not achievable in any other $L_\star$ galaxy. For this reason, the MW is a template for our understanding of galaxy formation. M31 is the only external galaxy that we can currently hope study in a level of detail approaching the MW. Studies of M31 have recently taken on greater significance, given the growing body of evidence that its formation history differs substantially from that of the MW. In an era of limited information about elemental abundances in M31, I have developed a technique to apply spectral synthesis to low-resolution stellar spectroscopy in order to measure abundances for individual giant stars in distant LG galaxies. Through undertaking the largest deep, spectroscopic survey of M31 to date with my collaborators, this has resulted in the first measurements of the elemental abundances in the inner stellar halo and stellar disk of M31, and the largest homogeneous catalog of elemental abundances in M31. With this foundational work, we have opened the doors to detailed studies of the chemical composition of M31. Now, we can begin to ask--and answer--what differences in the elemental abundances of the M31 and the MW imply for our knowledge of galaxy formation in the broader universe.
Although one-dimensional systems that exhibit translational symmetry are generally believed to exhibit anomalous heat transport, previous work has shown that the model of coupled rotators on a one-dimensional lattice constitute a possible exception. We investigate the equilibrium spatiotemporal correlations of energy and momentum of the rotator model, and find that both these fields diffuse normally. The normal diffusion is explained within the framework of stochastic hydrodynamics by observing that the angle variables do not constitute a conserved field, which leads to the absence of long-wavelength currents in the system. As an outcome of our analysis, we propose some general criteria for normal transport based on the existence of conservation laws.
We calculate the diameter and chirality dependences of the binding energies, sizes, and bright-dark splittings of excitons in semiconducting single-wall carbon nanotubes (SWNTs). Using results and insights from {\it ab initio} calculations, we employ a symmetry-based, variational method based on the effective-mass and envelope-function approximations using tight-binding wavefunctions. Binding energies and spatial extents show a leading dependence with diameter as $1/d$ and $d$, respectively, with chirality corrections providing a spread of roughly 20% with a strong family behavior. Bright-dark exciton splittings show a $1/d^2$ leading dependence. We provide analytical expressions for the binding energies, sizes, and splittings that should be useful to guide future experiments.
The intrinsic Baldwin effect is an anti-correlation between the line equivalent width and the flux of the underlying continuum detected in a single variable active galactic nucleus (AGN). This effect, in spite of the extensive research, is still not well understood, and might give us more information about the physical properties of the line and continuum emission regions in AGNs. Here we present preliminary results of our investigation of the intrinsic Baldwin effect of the broad H$\beta$ line in several Narrow-line Seyfert 1 (NLSy 1) galaxies, for which data were taken from the long-term monitoring campaigns and from the Sloan Digital Sky Survey Reverberation Mapping project.
In this work, we present the discovery and characterization of a new southern S-type symbiotic star, DeGaPe 35. We have obtained the low-resolution spectroscopic observations and supplemented them with photometry from Gaia DR3 and other surveys. The optical spectra of this target show prominent emission lines, including highly ionized [Fe VII] and O VI lines. The cool component of this symbiotic binary is an M4-5 giant with effective temperature ~ 3 380 - 3 470 K and luminosity ~ 3 000 L$_\odot$ (for the adopted distance of 3 kpc). The hot component is a shell-burning white dwarf. The photometric observations of the Gaia satellite, published recently in the Gaia DR3 suggested the variability with the period of about 700 - 800 days that we tentatively attributed to the orbital motion of the binary.
The subdivision graph $S(G)$ of a graph $G$ is the graph obtained by inserting a new vertex into every edge of $G$. In $\cite{PL}$, two classes of new corona graphs, the corona-vertex of the subdivision graph $G_{1}\diamondsuit G_{2}$ and corona-edge of the subdivision graph $G_{1}\star G_{2}$ were defined. The adjacency spectrum and the signless Laplacian spectrum of the two new graphs were computed when $G_{1}$ is an arbitrary graph and $G_{2}$ is an $r$-regular graph. In this paper, we give the formulate of the resistance distance and the Kirchhoff index in $G_{1}\diamondsuit G_{2}$ and $G_{1}\star G_{2}$ when $G_{1}$ and $G_{2}$ are arbitrary graphs. These results generalize them in $\cite{PL}$.
Ultra-Luminous X-ray sources are thought to be accreting black holes that might host Intermediate Mass Black Holes (IMBH), proposed to exist by theoretical studies, even though a firm detection (as a class) is still missing. The brightest ULX in M82 (M82 X-1) is probably one of the best candidates to host an IMBH. In this work we analyzed the data of the recent release of observations obtained from M82 X-1 taken by XMM-Newton. We performed a study of the timing and spectral properties of the source. We report on the detection of (46+-2) mHz Quasi-Periodic Oscillations (QPOs) in the power density spectra of two observations. A comparison of the frequency of these high-frequency QPOs with previous detections supports the 1:2:3 frequency distribution as suggested in other studies. We discuss the implications if the (46+-2) mHz QPO detected in M82 X-1 is the fundamental harmonic, in analogy with the High-Frequency QPOs observed in black hole binaries. For one of the observations we have detected for the first time a QPO at 8 mHz (albeit at a low significance), that coincides with a hardening of the spectrum. We suggest that the QPO is a milli-hertz QPO originating from the close-by transient ULX M82 X-2, with analogies to the Low-Frequency QPOs observed in black hole binaries.
Gildener-Weinberg (GW) models of electroweak symmetry breaking are especially interesting because the low mass and nearly Standard Model couplings of the $125\,{\rm GeV}$ Higgs boson, $H$, are protected by approximate scale symmetry. Another important but so far under-appreciated feature of these models is that a sum rule bounds the masses of the new charged and neutral Higgs bosons appearing in {\em all} these models to be below about $500\,{\rm GeV}$. Therefore, they are within reach of LHC data currently or soon to be in hand. Also so far unnoticed of these models, certain cubic and quartic Higgs scalar couplings vanish at the classical level. This is due to spontaneous breaking of the scale symmetry. These couplings become nonzero from explicit scale breaking in the Coleman-Weinberg loop expansion of the effective potential. In a two-Higgs doublet GW model, we calculate $\lambda_{HHH} \simeq 2(\lambda_{HHH})_{\rm SM} = 64\,{\rm GeV}$. This corresponds to $\sigma(pp \to HH) \cong 15$--$20\,{\rm fb}$, its {\em minimum} value for $\sqrt{s} = 13$--$14\,{\rm TeV}$ at the LHC. It will require at least the $27\,{\rm TeV}$ HE-LHC to observe this cross section. We also find $\lambda_{HHHH} \simeq 4(\lambda_{HHHH})_{\rm SM} = 0.129$, whose observation in $pp \to HHH$ requires a $100\,{\rm TeV}$ collider. Because of the above-mentioned sum rule, these results apply to {\em all} GW models. In view of this unpromising forecast, we stress that LHC searches for the new relatively light Higgs bosons of GW models are by far the surest way to test them in this decade.
The CP violating parameter epsilon'/epsilon is computed using the low-energy dynamics of a chiral theory supplemented by vector resonances. The divergent contributions coming from strong pi-pi scattering are tamed by vector-meson exchange terms. This amounts to softening the fast growing high-energy behaviour of pi-pi scattering. The final result for epsilon'/epsilon shows a smooth dependence on the cut-off where low energy dynamics is matched with that of QCD.
We treat the calculation of gravitational radiation using the mixed timelike-null initial value formulation of general relativity. The determination of an exterior radiative solution is based on boundary values on a timelike worldtube $\Gamma$ and on characteristic data on an outgoing null cone emanating from an initial cross-section of $\Gamma$. We present the details of a 3-dimensional computational algorithm which evolves this initial data on a numerical grid, which is compactified to include future null infinity as finite grid points. A code implementing this algorithm is calibrated in the quasispherical regime. We consider the application of this procedure to the extraction of waveforms at infinity from an interior Cauchy evolution, which provides the boundary data on $\Gamma$. This is a first step towards Cauchy-characteristic matching in which the data flow at the boundary $\Gamma$ is two-way, with the Cauchy and characteristic computations providing exact boundary values for each other. We describe strategies for implementing matching and show that for small target error it is much more computationally efficient than alternative methods.
In the learning based video compression approaches, it is an essential issue to compress pixel-level optical flow maps by developing new motion vector (MV) encoders. In this work, we propose a new framework called Resolution-adaptive Flow Coding (RaFC) to effectively compress the flow maps globally and locally, in which we use multi-resolution representations instead of single-resolution representations for both the input flow maps and the output motion features of the MV encoder. To handle complex or simple motion patterns globally, our frame-level scheme RaFC-frame automatically decides the optimal flow map resolution for each video frame. To cope different types of motion patterns locally, our block-level scheme called RaFC-block can also select the optimal resolution for each local block of motion features. In addition, the rate-distortion criterion is applied to both RaFC-frame and RaFC-block and select the optimal motion coding mode for effective flow coding. Comprehensive experiments on four benchmark datasets HEVC, VTL, UVG and MCL-JCV clearly demonstrate the effectiveness of our overall RaFC framework after combing RaFC-frame and RaFC-block for video compression.
We study globally supersymmetric 3d gauge theories on curved manifolds by describing the coupling of 3d topological gauge theories, with both Yang-Mills and Chern-Simons terms in the action, to background topological gravity. In our approach the Seifert condition for manifolds supporting global supersymmetry is elegantly deduced from the topological gravity BRST transformations. A cohomological characterization of the geometrical moduli which affect the partition function is obtained. In the Seifert context Chern-Simons topological (framing) anomaly is BRST trivial. We compute explicitly the corresponding local Wess-Zumino functional. As an application, we obtain the dependence on the Seifert moduli of the partition function of 3d supersymmetric gauge theory on the squashed sphere by solving the anomalous topological Ward identities, in a regularization independent way and without the need of evaluating any functional determinant.
We investigate the behavior of the periodic Anderson model in the presence of $d$-$f$ Coulomb interaction ($U_{df}$) using mean-field theory, variational calculation, and exact diagonalization of finite chains. The variational approach based on the Gutzwiller trial wave function gives a critical value of $U_{df}$ and two quantum critical points (QCPs), where the valence susceptibility diverges. We derive the critical exponent for the valence susceptibility and investigate how the position of the QCP depends on the other parameters of the Hamiltonian. For larger values of $U_{df}$, the Kondo regime is bounded by two first-order transitions. These first-order transitions merge into a triple point at a certain value of $U_{df}$. For even larger $U_{df}$ valence skipping occurs. Although the other methods do not give a critical point, they support this scenario.
The wide-area imaging surveys with the {\it Herschel} Space Observatory at sub-mm wavelengths have now resulted in catalogs of order one hundred thousand dusty, star-burst galaxies. We make a statistical estimate of $N(z)$ using a clustering analysis of sub-mm galaxies detected at each of 250, 350 and 500 $\mu$m from the Herschel Multi-tiered Extragalactic Survey (HerMES) centered on the Bo\"{o}tes field. We cross-correlate {\it Herschel} galaxies against galaxy samples at optical and near-IR wavelengths from the Sloan Digital Sky Survey (SDSS), the NOAO Deep Wide Field Survey (NDWFS) and the Spitzer Deep Wide Field Survey (SDWFS). We create optical and near-IR galaxy samples based on their photometric or spectroscopic redshift distributions and test the accuracy of those redshift distributions with similar galaxy samples defined with catalogs of the Cosmological Evolution Survey (COSMOS), as the COSMOS field has superior spectroscopy coverage. We model-fit the clustering auto and cross-correlations of {\it Herschel} and optical/IR galaxy samples to estimate $N(z)$ and clustering bias factors. The $S_{350} > 20$ mJy galaxies have a bias factor varying with redshift as $b(z)=1.0^{+1.0}_{-0.5}(1+z)^{1.2^{+0.3}_{-0.7}}$. This bias and the redshift dependence is broadly in agreement with galaxies that occupy dark matter halos of mass in the range of 10$^{12}$ to 10$^{13}$ M$_{\sun}$. We find that the redshift distribution peaks around $z \sim 0.5$ to 1 for galaxies selected at 250 $\mu$m with an average redshift of $< z > = 1.8 \pm 0.2$. For 350 and 500 $\mu$m-selected SPIRE samples the peak shifts to higher redshift, but the average redshift remains the same with a value of $1.9 \pm 0.2$.