bluuebunny/crossref_metadata_2025_split huggingface dataset:
Conformal transformations and conformal invariance in gravitation
Authors: Da̧browski M.P. , Garecki J. , Blaschke D.B. 
Published: June 2022

AbstractConformal transformations are frequently used tools in order to study relations between various theories of gravity and Einstein's general relativity theory. In this paper we discuss the rules of these transformations for geometric quantities as well as for the matter energy‐momentum tensor. We show the subtlety of the matter energy‐momentum conservation law which refers to the fact that the conformal transformation “creates” an extra matter term composed of the conformal factor which enters the conservation law. In an extreme case of the flat original spacetime the matter is “created” due to work done by the conformal transformation to bend the spacetime which was originally flat. We discuss how to construct the conformally invariant gravity theories and also find the conformal transformation rules for the curvature invariants R2, RabRab, RabcdRabcd and the Gauss‐Bonnet invariant in a spacetime of an arbitrary dimension. Finally, we present the conformal transformation rules in the fashion of the duality transformations of the superstring theory. In such a case the transitions between conformal frames reduce to a simple change of the sign of a redefined conformal factor.
Information in asset pricing: a wave function approach
Authors: Ishio H. , Haven E. 
Published: June 2022

AbstractThis paper introduces a quantum‐like wave function as an information wave function. We show how the option pricing partial differential equation can be re‐written when we account for such information wave function. We use two stochastic differential equations, one of which relates to Nelson's hypothesis of Universal Brownian motion. We also provide for two examples which further highlight the proposed theory.
Integrability and the variational formulation of non‐conservative mechanical systems
Authors: Delphenich D.H. 
Published: June 2022

AbstractIt is shown that one can obtain canonically‐defined dynamical equations for non‐conservative mechanical systems by starting with a first variation functional, instead of an action functional, and finding their zeroes. The kernel of the first variation functional, as an integral functional, is a 1‐form on the manifold of kinematical states, which then represents the dynamical state of the system. If the 1‐form is exact then the first variation functional is associated with the first variation of an action functional in the usual manner. The dynamical equations then follow from the vanishing of the dual of the Spencer operator that acts on the dynamical state. This operator, in turn, relates to the integrability of the kinematical states. The method is applied to the modeling of damped oscillators.
The odd couple: Boltzmann, Planck and the application of statistics to physics (1900–1913)
Authors: Badino M. 
Published: June 2022

AbstractIn the last forty years a vast scholarship has been dedicated to the reconstruction of Planck's theory of black‐body radiation and to the historical meaning of quantization. Since the introduction of quanta took place for combinatorial reasons, Planck's understanding of statistics must have played an important role. In the first part of this paper, I sum up the main theses concerning the status of the quantum and compare the arguments supporting them. In the second part, I investigate Planck's usage of statistical methods and the relation to Boltzmann's analogous procedure. I will argue that this way of attacking the problem is able to give us some interesting insights both on the theses stated by the historians and on the general meaning of Planck's theory.
Stripe segregation and magnetic coupling in the nickelate La5/3Sr1/3NiO4
Authors: Schwingenschlögl U. , Schuster C. , Frésard R. 
Published: June 2022

AbstractWe investigate the consequences of the stripe formation in the nickelate La5/3Sr1/3NiO4 for the details of its crystal structure and electronic states. Our data are based on numerical simulations within density functional theory (DFT) and the generalized gradient approximation (GGA). The on‐site Coulomb interaction is included in terms of the LDA+U scheme. Structure optimization of preliminary experimental data indicates a strong interaction between the structural and electronic degrees of freedom. In particular, we find a segregation of the diagonal filled stripes induced by a delicate interplay with the magnetic coupling. Beyond the cooperative effect of stripe segregation and spin order, distinct octahedral distortions are essential for the formation of an insulating state.
Deformation kinetics within cylindrical micropores of glassy solid 4He at very low temperatures
Authors: K.‐H. Chu Z. , Liu S.‐J. , Qin C. 
Published: June 2022

AbstractThe deformation kinetics for glassy solid helium confined in microscopic domain at very low temperature regime was investigated using a transition‐rate‐state dependent model considering the shear thinning behavior which means, once material being subjected to high shear rates, the viscosity diminishes with increasing shear rate. The preliminary results show that there might be nearly frictionless fields for rate of deformation due to the almost vanishing shear stress in micropores at very low temperature regime subjected to some surface conditions: The relatively larger roughness (compared to the macroscopic domain) inside micropores and the slip. As the pore size decreases, the surface‐to‐volume ratio increases and therefore, surface roughness will greatly affect the deformation kinetics in micropores. By using the boundary perturbation method, we obtained a class of temperature and activation energy dependent fields for the deformation kinetics at low temperature regime with the presumed small wavy roughness distributed along the walls of an cylindrical micropore. The critical deformation kinetics of the glassy matter is dependent upon the temperature, activation energy, activation volume, orientation dependent and is proportional to the (referenced) shear rate, the slip length, the amplitude and the orientation of the wavy‐roughness. Finally, we also discuss the quantitative similarity between our results with Ray and Hallock [Phys. Rev. Lett. 100, 235301 (2008)].
On the pre‐metric foundations of wave mechanics I: massless waves
Authors: Delphenich D.H. 
Published: June 2022

AbstractThe mechanics of wave motion in a medium are founded in conservation laws for the physical quantities that the waves carry, combined with the constitutive laws of the medium, and define Lorentzian structures only in degenerate cases of the dispersion laws that follow from the field equations. It is suggested that the transition from wave motion to point motion is best factored into an intermediate step of extended matter motion, which then makes the dimension‐codimension duality of waves and trajectories a natural consequence of the bicharacteristic (geodesic) foliation associated with the dispersion law. This process is illustrated in the conventional case of quadratic dispersion laws, as well as quartic ones, which include the Heisenberg–Euler dispersion law. It is suggested that the contributions to geodesic motion from the non‐quadratic nature of a dispersion law might represent another source of quantum fluctuations about classical extremals, in addition to the diffraction effects that are left out by the geometrical optics approximation.
Nonequilibrium quantum anharmonic oscillator and scalar field: high temperature approximations
Authors: Alvarez‐Estrada R.F. 
Published: June 2022

AbstractWe treat a relativistic quantum boson gas, described by a scalar quantum field, with quartic self‐interaction (ϕ4) in three spatial dimensions: we review the known equilibrium case and present new proposals off‐equilibrium. For high temperature and large spatial scales, the behaviour of the gas at equilibrium simplifies nonperturbatively (equilibrium dimensional reduction or EDR): its thermodynamics is described by classical statistical mechanics with some quantum field effects. By assumption, the initial state of the gas off‐equilibrium includes interactions and inhomogeneities and is not far from thermal equilibrium. We employ real‐time generating functionals and obtain the free nonequilibrium correlators at non‐zero temperature. The nonequilibrium quantum gas appears to simplify nonperturbatively in the regime of high temperature and large temporal and spatial scales (nonequilibrium dimensional reduction or NEDR), its dynamics being described by classical statistical mechanics with some quantum field effects. We outline the renormalization of the ϕ4 theory, the nonequilibrium statistical mechanics of a quantum anharmonic oscillator and the high temperature simplifications, all of which provide very useful hints for NEDR in the field case. Our main proposals are NEDR and the associated new (renormalized) real‐time nonequilibrium generating functionals for the ϕ4 theory.
Five‐dimensional relativity and extended elementary particles
Authors: Lessner G. 
Published: June 2022

AbstractFive‐dimensional relativity, based on the 5‐dimensional vacuum equations Rμν = 0, is interpreted as a general relativistic field theory describing the inner structure of extended elementary particles. The most general} spherically symmetric, purely electric and asymptotically flat solution of the field equations is calculated. The mass formula of this solution depends on two parameters h > 0 and q > 0, and the mass surface over the (h‐q)‐plane shows two slits at h= and

These slits can be tentatively identified as hadron branch for h= and lepton branch for

In the slits hadrons and leptons with their masses and extensions can be settled in local minima.
(0,2) Gauged linear sigma model on supermanifold
Authors: Okame Y. , Hayashi M.J. 
Published: June 2022

AbstractWe construct (0,2), D = 2 gauged linear sigma model on supermanifold with both an Abelian and non‐Abelian gauge symmetry. For the purpose of checking the exact supersymmetric (SUSY) invariance of the Lagrangian density, it is convenient to introduce a new operator for the Abelian gauge group. The operator provides consistency conditions for satisfying the SUSY invariance. On the other hand, it is not essential to introduce a similar operator in order to check the exact SUSY invariance of the Lagrangian density of non‐Abelian model, contrary to the Abelian one. However, we still need a new operator in order to define the (0,2) chirality conditions for the (0,2) chiral superfields. The operator can be defined from the conditions assuring the (0,2) supersymmetric invariance of the Lagrangian density in superfield formalism for the (0,2) U(N) gauged linear sigma model. We found consistency conditions for the Abelian gauge group which assure (0,2) supersymmetric invariance of Lagrangian density and agree with (0,2) chirality conditions for the superpotential. The supermanifold ℳ︁m|n becomes the super weighted complex projective space WCPm‐1|n in the U(1) case, which is considered as an example of a Calabi‐Yau supermanifold. The superpotential W(ϕ,ξ) for the non‐Abelian gauge group satisfies more complex condition for the SU(N) part, except the U(1) part of U(N), but does not satisfy a quasi‐homogeneous condition. This fact implies the need for taking care of constructing the Calabi‐Yau supermanifold in the SU(N) part. Because more stringent restrictions are imposed on the form of the superpotential than in the U(1) case, the superpotential seems to define a certain kind of new supermanifolds which we cannot identify exactly with one of the mathematically well defined objects.
The influence of self‐citation corrections and the fractionalised counting of multi‐authored manuscripts on the Hirsch index
Authors: Schreiber M. 
Published: June 2022

AbstractThe Hirsch index or h‐index is widely used to quantify the impact of an individual's scientific research output, determining the highest number h of a scientist's papers that received at least h citations. Fractionalised counting of the publications is an appropriate way to distribute the impact of a paper among all the coauthors of a multi‐authored manuscript in an easy way, leading to a simple modification hm of the h‐index. On the other hand the exclusion of self‐citations allows one to sharpen the index, what is appropriate, because self‐citations are usually not reflecting the significance of a publication. I have previously analysed the citation records of 26 physicists discussing the sharpened index hs as well as the modification hm of the original h‐index. In the present investigation I combine these two procedures yielding the modified sharpened index hms. For a better comparison, interpolated indices are utilized. The correlations between the indices are rather strong, but nevertheless the positions of some datasets change, in a few cases significantly, depending on whether they are put into order according to the values of h, hm, hs, or hms. This leads to the conclusion that the additional effort in determining the modified sharpened index hms is worth performing in order to obtain a fairer evaluation of the citation records.
Low‐frequency line temperatures of the CMB (Cosmic Microwave Background)
Authors: Hofmann R. 
Published: June 2022

AbstractBased on SU(2) Yang‐Mills thermodynamics we interprete Aracde2's and the results of earlier radio‐surveys on low‐frequency cosmic microwave background (CMB) line temperatures as a phase‐boundary effect. We explain the excess at low frequencies by evanescent, nonthermal photon fields of the CMB whose intensity is nulled by that of Planck distributed calibrator photons. The CMB baseline temperature thus is identified with the critical temperature of the deconfining‐preconfining transition.
Nonlocal transformations for accelerated observers
Authors: Mashhoon B. 
Published: June 2022

AbstractAccording to the locality postulate of special relativity, the measurements of physical fields by accelerated observers at a given event in Minkowski spacetime are related to each other by the representations of the Lorentz group. Nonlocal extensions of these representations are necessary, however, once acceleration‐induced nonlocality is taken into account. The particular case of Dirac spinors is treated in detail and the corresponding nonlocal transformation group is studied.
Indefinite oscillators and black‐hole evaporation
Authors: Kiefer C. , Marto J. , Moniz P.V. 
Published: June 2022

AbstractWe discuss the dynamics of two harmonic oscillators of which one has a negative kinetic term. This model mimics the Hamiltonian in quantum geometrodynamics, which possesses an indefinite kinetic term. We solve for the time evolution in both the uncoupled and coupled case. We use this setting as a toy model for studying some possible aspects of the final stage of black‐hole evaporation. We assume that one oscillator mimics the black hole, while the other mimics Hawking radiation. In the uncoupled case, the negative term leads to a squeezing of the quantum state, while in the coupled case, which includes back reaction, we get a strong entangled state between the mimicked black hole and the radiation. We discuss the meaning of this state. We end by analyzing the limits of this model and its relation to more fundamental approaches.
Manifestly covariant classical correlation dynamics I. General theory
Authors: Tian C. 
Published: June 2022

AbstractIn this series of papers we substantially extend investigations of Israel and Kandrup on nonequilibrium statistical mechanics in the framework of special relativity. This is the first one devoted to the general mathematical structure. Based on the action‐at‐a‐distance formalism we obtain a single‐time Liouville equation. This equation describes the manifestly covariant evolution of the distribution function of full classical many‐body systems. For such global evolution the Bogoliubov functional assumption is justified. In particular, using the Balescu‐Wallenborn projection operator approach we find that the distribution function of full many‐body systems is completely determined by the reduced one‐body distribution function. A manifestly covariant closed nonlinear equation satisfied by the reduced one‐body distribution function is rigorously derived. We also discuss extensively the generalization to general relativity especially an application to self‐gravitating systems.
Ageing in granular aluminium insulating thin films
Authors: Delahaye J. , Grenet T. 
Published: June 2022

AbstractWe present a new set of electrical field effect measurements on granular aluminium insulating thin films. We have explored how the conductance relaxations induced by gate voltage changes depend on the age of the system, namely the time elapsed since its quench at low temperature. A clear age dependence of the relaxations is seen, qualitatively similar to ageing effects seen in other well studied glassy systems such as spin glasses or polymers. We explain how our results differ from the previous ones obtained with different protocols in indium oxide and granular aluminium thin films. Our experimental findings bring new information on the dynamics of the system and put new constraints on the theoretical models that may explain slow conductance relaxations in disordered insulators.
1/f noise and slow relaxations in glasses
Authors: Amir A. , Oreg Y. , Imry Y. 
Published: June 2022

AbstractRecently we have shown that slow relaxations in the electron glass system can be understood in terms of the spectrum of a matrix describing the relaxation of the system close to a metastable state. The model focused on the electron glass system, but its generality was demonstrated on various other examples. Here, we study the noise spectrum in the same framework. We obtain a remarkable relation between the spectrum of relaxation rates λ described by the distribution function P (λ) ∼ 1/λ and the 1/f noise in the fluctuating occupancies of the localized electronic sites. This noise can be observed using local capacitance measurements. We confirm our analytic results using numerics, and also show how the Onsager symmetry is fulfilled in the system.
Numerical study of the equilibrium thermodynamics of the Coulomb glass
Authors: Goethe M. , Palassini M. 
Published: June 2022

AbstractWe discuss the results of large‐scale Monte Carlo simulations of the lattice Coulomb glass model. Using the Exchange Monte Carlo algorithm we are able to equilibrate the system to very low temperature and obtain evidence against the existence of an equilibrium glass transition in three dimensions (3D). We also discuss results for the 3D Random Field Ising model that highlight the role of the interaction range. Finally, we report results for the 2D Coulomb glass, which show a behaviour very similar to the 3D case.
Study of two‐electron jumps in relaxation of Coulomb glasses
Authors: Bergli J. , Somoza A.M. , Ortuño M. 
Published: June 2022

AbstractA long‐standing debate in the theory of hopping insulators concerns the role of multi‐electron transitions in the dynamics of the system. The natural assumption is that as temperature is lowered, two‐electron transitions will play an increasingly important role since they provide a way of tunneling through additional energy barriers which would be energetically unfavorable as successive one‐electron transitions. This was disputed in [1], but later it was seen in [2]. The reason for this discrepancy is not clear and deserves further attention. One point where the two approaches diverged was in the selection and weighting of the two‐electron transitions relative to one‐electron transitions. We present calculations of the transition rates to second order in the tunneling matrix element, which will be used in improved numerical studies. We compare results for only one‐electron jumps with results including also two‐electron jumps.
Effect of Fabry‐Perot resonances in disordered one‐dimensional array of alternating dielectric bi‐layers
Authors: Luna‐Acosta G.A. , Makarov N.M. 
Published: June 2022

AbstractWe study numerically and analytically the role of Fabry‐Perot resonances in the transmission through a one‐dimensional finite array formed by two alternating dielectric slabs. The disorder consists in varying randomly the width of one type of layers while keeping constant the width of the other type. Our numerical simulations show that localization is strongly inhibited in a wide neighborhood of the Fabry‐Perot resonances. Comparison of our numerical results with an analytical expression for the average transmission, derived for weak disorder and finite number of cells, reveals that such expression works well even for medium disorder up to a certain frequency. Our results are valid for photonic and phononic one‐dimensional disordered crystals, as well as for semiconductor superlattices.
Scaling law and critical exponent for α0 at the 3D Anderson transition
Authors: Vasquez L.J. , Slevin K. , Rodriguez A. , Roemer R.A. 
Published: June 2022

AbstractWe use high‐precision, large system‐size wave function data to analyse the scaling properties of the multifractal spectra around the disorder‐induced three‐dimensional Anderson transition in order to extract the critical exponents of the transition. Using a previously suggested scaling law, we find that the critical exponent ν is significantly larger than suggested by previous results. We speculate that this discrepancy is due to the use of an oversimplified scaling relation.
Spin‐dependent‐magnetoresistance control by regulation of heat treatment temperature for magnetite nano‐particle sinter
Authors: Kobori H. , Asahi T. , Yamasaki Y. , Sugimura A. , Taniguchi T. , Ando A. , Kawanaka H. , Naitoh Y. , Shimizu T. 
Published: June 2022

AbstractThe control of spin‐dependent‐magnetoresistance by regulation of the heat treatment (HT) temperature for magnetite (Fe3O3) nano‐particle sinter (MNPS) has been studied. The average nano‐particle size in the MNPS is 30nm and the HT was carried out from 400°C to 800°C. The HT of the MNPS varies the coupling form between adjacent magnetite nano‐particles and the crystallinity of that. The measurements on electrical resistance (ER), magnetoresistance (MR) and magnetization were performed between 4K and 300K. The behavior of the ER and MR considerably changes at the HT temperature of ∼600°C. Below ∼600°C the ER indicates the variable‐range‐hopping conduction behavior and the MR shows the large intensity in a wide temperature region. Above ∼600°C the ER shows the indication of the Verwey transition near 110K like a bulk single crystal and the MR designates the smaller intensity. We consider that below ∼600°C the ER and MR are dominated by the grain‐boundary conduction and above ∼600°C those are determined by the inter‐grain conduction. The magnetic field application to the grain‐boundary region is inferred to cause the large enhancement of the MR.
Magnetoresistance in dilute p‐Si/SiGe in parallel and tilted magnetic fields
Authors: Drichko I.L. , Smirnov I.Yu. , Suslov A.V. , Mironov O.A. , Leadley D.R. 
Published: June 2022

AbstractWe report the results of an experimental study of the magnetoresistance ρxx and ρxy in two samples of p‐Si/SiGe with low carrier concentrations p = 8.2 × 1010 cm‐2 and p = 2 × 1011 cm‐2. The research was performed in the temperature range of 0.3–2 K and in the magnetic fields of up to 18 T, parallel or tilted with respect to the two‐dimensional (2D) channel plane. The large in‐plane magnetoresistance can be explained by the influence of the in‐plane magnetic field on the orbital motion of the charge carriers in the quasi‐2D system. The measurements of ρxx and ρxy in the tilted magnetic field showed that the anomaly in ρxx, observed at filling factor ν = 3/2 is practically nonexistent in the conductivity σxx. The anomaly in σxx at ν = 2 might be explained by overlapping of the levels with different spins 0 ↑ and 1 ↓ when the tilt angle of the applied magnetic field is changed. The dependence of g‐factor g*(Θ)/g*(00) on the tilt angle Θ was determined.