ShantanuT01/DACTYL-Pretraining huggingface dataset:
Because of the rotational invariance of the nuclear Hamiltonian, there exists a density functional for nuclei that depends only on two scalar densities. Practical calculations boil down to radial, one-dimensional ones.
We review the standards of relativistic quantum mechanics such as the Dirac equation under the concept of negative masses. We show that negative energies are acceptable provided the masses are simultaneously negative. Negative energy and mass anti fermions are obtained from positive energy and mass fermions through a unitary PT transformation.
The quantum deformed (1+1) Poincare' algebra is shown to be the kinematical symmetry of the harmonic chain, whose spacing is given by the deformation parameter. Phonons with their symmetries as well as multiphonon processes are derived from the quantum group structure. Inhomogeneous quantum groups are thus proposed as kinematical invariance of discrete systems.
We prove that the genus $g$, the relative irregularity $q_f$ and the Clifford index $c_f$ of a non-isotrivial fibration $f$ satisfy the inequality $q_f \leq g - c_f$. This gives in particular a proof of Xiao's conjecture for fibrations whose general fibres have maximal Clifford index.
Recently, it has been proposed by Maldacena that large $N$ limits of certain conformal field theories in $d$ dimensions can be described in terms of supergravity (and string theory) on the product of $d+1$-dimensional $AdS$ space with a compact manifold. Here we elaborate on this idea and propose a precise correspondence between conformal field theory observables and those of supergravity: correlation functions in conformal field theory are given by the dependence of the supergravity action on the asymptotic behavior at infinity. In particular, dimensions of operators in conformal field theory are given by masses of particles in supergravity. As quantitative confirmation of this correspondence, we note that the Kaluza-Klein modes of Type IIB supergravity on $AdS_5\times {\bf S}^5$ match with the chiral operators of $\N=4$ super Yang-Mills theory in four dimensions. With some further assumptions, one can deduce a Hamiltonian version of the correspondence and show that the $\N=4$ theory has a large $N$ phase transition related to the thermodynamics of $AdS$ black holes.
The quality of a quantum operation determines the performance of quantum information processing, such as the sensitivity of quantum sensing. Different from the fidelity of quantum operation in quantum computation, we present an effective function to evaluate the performance and diagnose the imperfection of operations in multi-pulse based quantum sensing. The evaluation function directly links the realistic sensitivity with intrinsic sensitivity in a simple way. Moreover, guided by this evaluation function, we optimize a composite pulse sequence for high sensitivity nitrogen-vacancycenter based magnetometry against spectrum inhomogeneities and control errors to improve the signal-to-noise ratio of nanoscale nuclear magnetic resonance by 1 order of magnitude. It marks an important step towards quantitative quantum sensing with imperfect quantum control in practical applications.
MgO-barrier magnetic tunnel junctions with half-metallic Heusler alloy electrodes attracted much attentions for spintronics applications. However, a couples of issues related to materials still remain to be resolved for practical uses. Recently, quarterly equiatomic Heusler alloys attracted attentions as advanced Heusler alloys. CoIrMnZ (Z = Al, Si, Ga, and Ge) half-metallic Heusler alloys were designed and predicted to have moderate Curie temperatures and to be a lattice-matched with the MgO barrier, being advantageous to traditional Co2 Heusler alloys [T. Roy et al., J. Magn. Magn. Mater. 498, 166092 (2020)]. Here we experimentally investigated structure and magnetic properties for thin films of one of those alloys, CoIrMnAl with a sputtering deposition. We successfully obtained the films with the B2 chemical ordering even with no post-annealing process. The lattice constant for the films annealed at 500-600$^\circ$C approximates the predicted values. The magnetization at 10 K was near 500 kA/m and the Curie temperature was approximately 400 K were observed, which were about 70% of the values predicted for the fully ordered structure. The magnetic properties observed in those B2 ordered films were well explained by ferrimagnetism appeared in B2 ordered CoIrMnAl with full-swap disorders of Co-Ir and Mn-Al and almost full-swap disorder of Co-Mn, predicted from the first-principles calculations.
This paper is concerned with the fractional evolution equation with a discrete distribution of Caputo time-derivatives such that the largest and the smallest orders, $\alpha$ and $\alpha_m$, satisfy the conditions $1<\alpha\le 2$ and $\alpha-\alpha_m\le 1$. First, based on a study of the related propagation function, the nonnegativity of the fundamental solutions to the spatially one-dimensional Cauchy and signaling problems is proven and propagation speed of a disturbance is discussed. Next, we study the equation with a general linear spatial differential operator defined in a Banach space and suppose it generates a cosine family. A subordination principle is established, which implies the existence of a unique solution and gives an integral representation of the solution operator in terms of the corresponding cosine family and a probability density function. Explicit representation of the probability density function is derived. The subordination principle is applied for obtaining regularity results. The analytical findings are supported by numerical work.
We argue that quite unusual properties of Quark-Gluon Plasma in the RHIC temperature domain $T=(1-2)T_c$ are consequences of the approximate equilibrium between electric and magnetic sectors reached above the deconfinement temperature. Already classical study of few body motion in a electric-magnetic plasma shows abnormally large scattering rate due to the so called ``magnetic bottle'' effect. Molecular dynamics simulation have found that equal mixture of electric and magnetic quasiparticles do produce plasmas of small viscosity and even smaller diffusion rate, comparable to what is needed to explain RHIC data and also to what follows from AdS/CFT.   As a separate issue, we point out that right above $T_c$ there should be surviving s-wave baryons made of quarks ($N,\Delta$), as well as adjoint objects, 3-gluon and 3-monopole chains (the latter being nothing else but ``calorons'' or finite-T instantons).
The success of the identification of the planar dilatation operator of N=4 SYM with an integrable spin chain Hamiltonian has raised the question if this also is valid for a deformed theory. Several deformations of SYM have recently been under investigation in this context. In this work we consider the general Leigh-Strassler deformation. For the generic case the S-matrix techniques cannot be used to prove integrability. Instead we use R-matrix techniques to study integrability. Some new integrable points in the parameter space are found.
Using $1/S$ expansion, we discuss the magnon spectrum of Heisenberg antiferromagnet (AF) on a simple cubic lattice with small dipolar interaction at small temperature $T\ll T_N$, where $T_N$ is the Neel temperature. Similar to 3D and 2D ferromagnets, quantum and thermal fluctuations renormalize greatly the bare gapless spectrum leading to a gap $\Delta\sim \omega_0$, where $\omega_0$ is the characteristic dipolar energy. This gap is accompanied by anisotropic corrections to the free energy which make the cube edges easy directions for the staggered magnetization (dipolar anisotropy). In accordance with previous results, we find that dipolar forces split the magnon spectrum into two branches. This splitting makes possible two types of processes which lead to a considerable enhance of the damping compared to the Heisenberg AF: a magnon decay into two other magnons and a confluence of two magnons. It is found that magnons are well defined quasiparticles in quantum AF. We demonstrate however that a small fraction of long-wavelength magnons can be overdamped in AFs with $S\gg1$ and in quantum AFs with a single-ion anisotropy competing with the dipolar anisotropy. Particular materials are pointed out which can be suitable for experimental observation of this long-wavelength magnons breakdown that contradicts expectation of the quasiparticle concept.
Quantum teleportation is studied in noninertial frame, for fermionic case, when Alice and Bob share a general nonclassical correlated state. In noninertial frames two fidelities of teleportation are given. It is found that the average fidelity of teleportation from a separable and nonclassical correlated state is increasing with the amount of nonclassical correlation of the state. However, for any particular nonclassical correlated state, the fidelity of teleportation decreases by increasing the acceleration.
What should be the quasinormal modes associated with a spacetime that contains a naked singularity instead of a black hole? In the present work we address this problem by studying the scattering of scalar fields on a curved background described by a Reissner-Nordstr\"om spacetime with $|q| > m$. We show that there is a qualitative difference between cases with $1 < q^2/m^2 \lesssim 9/8$ and cases with $q^2/m^2 \gtrsim 9/8$. We discuss the necessary conditions for the well-posedness of the problem, and present results for the low damped modes in the low $l$ and large $l$ limit. We also consider the asymptotically highly damped quasinormal modes. We present strong evidence that such modes are absent in the case of a naked Reissner-Nordstr\"om singularity, corroborating recent conjectures relating them to classical and quantum properties of horizons.
The quantum interest conjecture of Ford and Roman asserts that any negative-energy pulse must necessarily be followed by an over-compensating positive-energy one within a certain maximum time delay. Furthermore, the minimum amount of over-compensation increases with the separation between the pulses. In this paper, we first study the case of a negative-energy square pulse followed by a positive-energy one for a minimally coupled, massless scalar field in two-dimensional Minkowski space. We obtain explicit expressions for the maximum time delay and the amount of over-compensation needed, using a previously developed eigenvalue approach. These results are then used to give a proof of the quantum interest conjecture for massless scalar fields in two dimensions, valid for general energy distributions.
The nature of some GRB host galaxies has been investigated by means of chemical evolution models of galaxies of different morphological type following the evolution of the abundances of H, He, C, N, O, $\alpha$-elements, Ni, Fe, Zn, and including also the evolution of dust. By comparing predictions with abundance data, we were able to constrain nature and age of GRB hosts. We also computed a theoretical cosmic dust rate, including stellar dust production, accretion and destruction, under the hypotheses of pure luminosity evolution and strong number density evolution of galaxies. We suggest that one of the three GRB hosts is a massive proto-spheroid catched during its formation, while for the other two the situation is more uncertain, although one could perhaps be a spheroid and the other a spiral galaxy. We estimated the chemical ages of the host galaxies which vary from 15 to 320 Myr. Concerning the cosmic effective dust production rate in an unitary volume of the Universe, our results show that in the case of pure luminosity evolution there is a first peak between redshift $z=8$ and $9$ and another at $z\sim 5$, whereas in the case of strong number density evolution it increases slightly from $z=10$ to $z\sim 2$ and then it decreases down to $z=0$. Finally, we found tha the total cosmic dust mass density at the present time is: $\Omega_{dust} \sim 3.5\cdot 10^{-5}$in the case of pure luminosity evolution and $\Omega_{dust} \sim 7\cdot 10^{-5}$ in the case of number density evolution.
We introduce a novel approach to study the critical behavior of equilibrium and non-equilibrium systems which is based on the concept of an instantaneous correlation length. We analyze in detail two classical statistical mechanical systems: the XY model and the Ising model, and one of the prototype models of Self-Organized Criticality: the forest fire model (FFM). The proposed method can both capture the critical behavior of the XY model and the Ising model and discriminate between the nature of the phase transition in the two scenarios. When applied to the FFM, it gives surprising results, suggesting that the model could be critical despite displaying broken scaling in the distribution of cluster sizes.
We determine reductions of 2-dimensional, irreducible, semi-stable, and non-crystalline representations of $\mathrm{Gal}(\overline{\mathbb Q}_p/\mathbb Q_p)$ with Hodge--Tate weights $0 < k-1$ and with $\mathcal L$-invariant whose $p$-adic norm is sufficiently large, depending on $k$. Our main result provides the first systematic examples of the reductions for $k \geq p$.
The interstellar medium feeds both the formation of stars and the growth of black holes, making it a key ingredient in the evolution of galaxies. With the advent of the Atacama Large Millimeter/ submillimeter Array (ALMA), we can now probe the interstellar medium within high-redshift galaxies in increasingly exquisite detail. Our recent ALMA observations map the molecular gas and dust continuum emission in sub-millimetre-selected galaxies on 1-5 kpc scales, revealing significant differences in how the gas, dust continuum, and existing stellar emission are distributed within the galaxies. This study demonstrates the power of ALMA to shed new light on the structure and kinematics of the interstellar medium in the early Universe, suggesting that the interpretation of such observations is more complex than typically assumed.
The physical properties of the edge states of the cut two-leg spin ladder are investigated by means of the bosonization approach. By carefully treating boundary conditions, we derive the existence of spin-1/2 edge states in the spin ladder with a ferromagnetic rung exchange and for the open spin-1 Heisenberg chain. In contrast, such states are absent in the antiferromagnetic rung coupling case. The approach, based on a mapping onto decoupled semi-infinite off-critical Ising models, allows us to compute several physical quantities of interest. In particular, we determine the magnetization and dimerization profiles of the cut two-leg spin ladder and of the open biquadratic spin-1 chain in the vicinity of the SU(2)$_2$ WZNW critical point.
We introduce the notion of a generalized oscillating tableau and define a promotion operation on such tableaux that generalizes the classical promotion operation on standard Young tableaux. As our main application, we show that this promotion corresponds to rotation of the irreducible $A_2$-webs of G. Kuperberg.
In this contribution we discuss briefly a few calibration items relevant to the data analysis and present some preliminary scientific results. The discussion on instrumental topics focuses on the response matrix and Point Spread Function (PSF). In the scientific results section we discuss a first analysis of the two Seyferts MCG 6-30-15 and NGC 4151 and of the Cosmic X-ray Background.
The poset Ramsey number $R(Q_m,Q_n)$ is the smallest integer $N$ such that any blue-red coloring of the elements of the Boolean lattice $Q_N$ has a blue induced copy of $Q_m$ or a red induced copy of $Q_n$. The weak poset Ramsey number $R_w(Q_m,Q_n)$ is defined analogously, with weak copies instead of induced copies. It is easy to see that $R(Q_m,Q_n) \ge R_w(Q_m,Q_n)$.   Axenovich and Walzer showed that $n+2 \le R(Q_2,Q_n) \le 2n+2$. Recently, Lu and Thompson improved the upper bound to $\frac{5}{3}n+2$. In this paper, we solve this problem asymptotically by showing that $R(Q_2,Q_n)=n+O(n/\log n)$.   In the diagonal case, Cox and Stolee proved $R_w(Q_n,Q_n) \ge 2n+1$ using a probabilistic construction. In the induced case, Bohman and Peng showed $R(Q_n,Q_n) \ge 2n+1$ using an explicit construction. Improving these results, we show that $R_w(Q_m,Q_n) \ge n+m+1$ for all $m \ge 2$ and large $n$ by giving an explicit construction; in particular, we prove that $R_w(Q_2,Q_n)=n+3$.
We explore the redshift evolution of the metal content of damped Lyman alpha systems (DLAs) with new observations of four absorbers at z < 1.5 . The main conclusion is that the column density--weighted mean metallicity, [<Zn/H>] = -1.03 +/- 0.23 (on a logarithmic scale), is not significantly higher at z < 1.5 than at earlier epochs, despite the fact that the comoving star formation rate density of the universe was near its maximum value at this redshift. For three of the four DLAs our observations include absorption lines of Si, Mn, Cr, Fe, and Ni, as well as Zn. We argue that the relative abundances of these elements are consistent with a moderate degree of dust depletion which, once accounted for, leaves no room for the enhancement of the alpha-elements over iron seen in metal poor stars in the Milky Way. This is contrary to previous assertions that DLAs have been enriched solely by Type II supernovae, but can be understood if the rate of star formation in the systems studied proceeded more slowly than in the early history of our Galaxy. These results add to a growing body of data all pointing to the conclusion that known DLAs do not trace the galaxy population responsible for the bulk of star formation. Possible reasons are that sight-lines through metal rich gas are systematically underrepresented because the background QSOs are reddened, and that the most actively star forming galaxies are also the most compact, presenting too small a cross-section to have been probed yet with the limited statistics of current samples.
We derive the one loop renormalization group equations for the Cabibbo-Kobayashi-Maskawa matrix for the Standard Model, its two Higgs extension and the minimal supersymmetric extension in a novel way. The derived equations depend only on a subset of the model parameters of the renormalization group equations for the quark Yukawa couplings so the CKM matrix evolution cannot fully test the renormalization group evolution of the quark Yukawa couplings. From the derived equations we obtain the invariant of the renormalization group evolution for three models which is the angle $\alpha$ of the unitarity triangle. For the special case of the Standard Model and its extensions with $v_{1}\approx v_{2}$ we demonstrate that also the shape of the unitarity triangle and the Buras-Wolfenstein parameters $\bar{\rho}=(1-{1/2}\lambda^{2})\rho$ and $\bar{\eta}=(1-{1/2}\lambda^{2})\eta$ are conserved. The invariance of the angles of the unitarity triangle means that it is not possible to find a model in which the CKM matrix might have a simple, special form at asymptotic energies.
The boundary conditions for canonical vacuum general relativity is investigated at the quasi-local level. It is shown that fixing the area element on the 2- surface S (rather than the induced 2-metric) is enough to have a well defined constraint algebra, and a well defined Poisson algebra of basic Hamiltonians parameterized by shifts that are tangent to and divergence-free on $. The evolution equations preserve these boundary conditions and the value of the basic Hamiltonian gives 2+2 covariant, gauge-invariant 2-surface observables. The meaning of these observables is also discussed.
Differently from 2D image datasets such as COCO, large-scale human datasets with 3D ground-truth annotations are very difficult to obtain in the wild. In this paper, we address this problem by augmenting existing 2D datasets with high-quality 3D pose fits. Remarkably, the resulting annotations are sufficient to train from scratch 3D pose regressor networks that outperform the current state-of-the-art on in-the-wild benchmarks such as 3DPW. Additionally, training on our augmented data is straightforward as it does not require to mix multiple and incompatible 2D and 3D datasets or to use complicated network architectures and training procedures. This simplified pipeline affords additional improvements, including injecting extreme crop augmentations to better reconstruct highly truncated people, and incorporating auxiliary inputs to improve 3D pose estimation accuracy. It also reduces the dependency on 3D datasets such as H36M that have restrictive licenses. We also use our method to introduce new benchmarks for the study of real-world challenges such as occlusions, truncations, and rare body poses. In order to obtain such high quality 3D pseudo-annotations, inspired by progress in internal learning, we introduce Exemplar Fine-Tuning (EFT). EFT combines the re-projection accuracy of fitting methods like SMPLify with a 3D pose prior implicitly captured by a pre-trained 3D pose regressor network. We show that EFT produces 3D annotations that result in better downstream performance and are qualitatively preferable in an extensive human-based assessment.
We demonstrate that it is possible to perform face-related computer vision in the wild using synthetic data alone. The community has long enjoyed the benefits of synthesizing training data with graphics, but the domain gap between real and synthetic data has remained a problem, especially for human faces. Researchers have tried to bridge this gap with data mixing, domain adaptation, and domain-adversarial training, but we show that it is possible to synthesize data with minimal domain gap, so that models trained on synthetic data generalize to real in-the-wild datasets. We describe how to combine a procedurally-generated parametric 3D face model with a comprehensive library of hand-crafted assets to render training images with unprecedented realism and diversity. We train machine learning systems for face-related tasks such as landmark localization and face parsing, showing that synthetic data can both match real data in accuracy as well as open up new approaches where manual labelling would be impossible.
Understanding heat transfer between a quantum system and its environment is of undisputed importance if reliable quantum devices are to be constructed. Here, we investigate the heat transfer between system and bath in non-Markovian open systems in the process of adiabatic speedup. Using the quantum state diffusion equation method, the heat current, energy current, and power are calculated during free evolution and under external control of the system. While the heat current increases with increasing system-bath coupling strength and bath temperature, it can be restricted by the non-Markovian nature of the bath. Without pulse control, the heat current is nearly equal to the energy current. On the other hand, with pulse control, the energy current turns out to be nearly equal to the power. In this scenario, we show that non-Markovianity is a useful tool to drive the system through an approximate adiabatic dynamics, with pulse control acting in the conversion between heat current and power throughout the evolution.
We prove two results of strong continuity with respect to the initial datum for bounded solutions to the Euler equations in vorticity form. The first result provides sequential continuity and holds for a general bounded solution. The second result provides uniform continuity and is restricted to H\"older continuous solutions.
The sum formula is a well known relation in the field of the multiple zeta values. In this paper, we present its generalization for the Euler-Zagier multiple zeta function.
The paper explains the method to determine a short unit cell attached to any hyperplane given by its integer vector $\mathbf{p}$. Equivalently, it gives all the solutions of the $N$-dimensional Bezout identity associated with the coordinates of $\mathbf{p}$.