Search

The possibility of the existence of multiquark hadrons made of 4-quarks for mesons and 5-quarks for baryons was predicted by Gell-Mann [Phys. Lett. 8, 214 (1964)]. The renewed interest for the search for exotic pentaquark states was initiated by the paper by Diakonov, Petrov, and Polyakov [Z. Phys. A 359, 305 (1997)]. The 2003 experimental reports on the observation of Θ + pentaquark with u u d d s ̄ quark content created a great excitement and many following experiments have reported its observation [K. H. Hicks, Eur. Phys. J. H 37, 1 (2012)]. After high-statistics experiments at JLab, which did not confirm previous claims by the CLAS collaboration, the community concluded that the Θ + pentaquark either does not exist at all or has an extremely small cross-section, making it currently unobserved. There were different review papers on this subject, questioning the existence of Θ + or trying to explain the reasons why reaching a conclusion based on production experiments is challenging [M. Amaryan, Eur. Phys. J. Plus 137, 684 (2022)]. To address the challenge of minimal 3-body final states, a formation experiment with a projectile-kaon beam is proposed. In the following, we discuss how the Θ + could be observed in the K L p → Θ + → K + n reaction in the KLF experiment at JLab [M. Amaryan et al. [KLF Collaboration], arXiv:2008.08215 [nucl-ex]]. [ABSTRACT FROM AUTHOR]

In this paper, we discuss the inflationary magnetogenesis scenario, in which the coupling function is introduced to break the conformal invariance of electromagnetic action. Unlike in conventional models, we deduce the Maxwell's equations under the perturbed Friedmann–Robertson–Walker metric. We found that the self-consistency of the action depends on the form of the coupling function when the scalar mode perturbations have been considered. Therefore, this self-consistency can be seen as a restriction on the coupling function. In this paper, we give the restrictive equation for coupling function then obtain the specific form of the coupling function in a simple model. We found that the coupling function depends on the potential of the inflaton and thus is model-dependent. We obtain the power spectrum of electric field and magnetic field in large-field inflation model. We also found that the coupling function is an increasing function of time during slow-roll era as most of inflationary magnetogenesis models, it will lead to strong coupling problem. This issue is discussed qualitatively by introducing a correction function during the preheating. [ABSTRACT FROM AUTHOR]

Various heavy quarkonium states can be employed as a testing ground for the magnetic field created and later possibly persisted in heavy ion collision (HIC) experiments. In this paper, we have shown the modification in the binding energies, and ionization potentials categorically for different species of quarkonia in the medium in the presence of a magnetic field. For the study, we have considered quarkonium states which are well described by the real-valued effective potential in the thermal medium which is evolving by respecting the hydrodynamical power law. Furthermore while addressing the issue of their survival, we have not ignored the possibility of transitions between various bound-to-bound and bound-to-unbound states for different charmonium and bottomonium states. Our analysis shows that this phenomenon can be considered as a benchmark for understanding the presence, strength and persistence of the magnetic field which is expected to be produced through the high-energy nucleus–nucleus collisions. [ABSTRACT FROM AUTHOR]

In this paper, we study the class of the processes, where dynamics depends essentially on the properties of the hadron wave functions involved in the reactions. In this case, the momentum dependence of the form of the wave functions, imposed by the Lorentz invariance and in particular by the Lorentz contraction, can be tested in the experiment and may strongly influence the resulting cross-sections. One example of such observables is given by the hadron form factors in the case when the large Q behavior is mostly frozen, while the Lorentz contraction of the hadron wave functions is taken into account. Another example, considered earlier, is the strong hadron decay with high-energy emission. In this paper, we study the role of the Lorentz contraction in the high-energy hadron–hadron scattering process at large momentum transfer. For the p p and p p ̄ scattering at large s , it is shown that at small − t ≪ s , the picture of two exponential slopes in the differential cross-section, explained previously by the author, remains stable, while the backward scattering cross-section is strongly increased by the Lorentz contraction. [ABSTRACT FROM AUTHOR]

In this paper, an opportunity to generate beyond Horndeski interactions is addressed. An amplitude generating a certain beyond Horndeski coupling is explicitly found. The amplitude is free from ultraviolet divergences, so it is protected from ultraviolet contributions and can be considered as a universal prediction of effective field theory. [ABSTRACT FROM AUTHOR]

Recently great interest has been devoted toward a better understanding of a possible deep relation between large size structures we observe today in the universe and the quantum fluctuations at Planck time. Within such a context this paper provides us with a procedure for how to obtain a faithful description of the Bohr energy levels for hydrogen like atoms, starting from a generalization of a quantum relation for primordial black holes' masses at Planck time. The key role of quantum mechanics in such a description is emphasized and the classical correspondence taking us from Newton's law for interacting masses to Coulomb's law for interacting charges evidenced. [ABSTRACT FROM AUTHOR]

This paper further studies the cosmological evolution and geometry diagnosis of Barrow holographic dark energy (BHDE) in the DGP braneworld, specifically, by choosing the interaction between dark energy and dark matter item. Q 1 = 3 H ξ ρ de , Q 2 = 3 H ξ ρ dm , Q 3 = 3 H ξ ρ de 2 / (ρ de + ρ dm ) , Q 4 = 3 H ξ ρ dm 2 / (ρ de + ρ dm ) are discussed in the case of no interaction and four different interactions, the evolution laws of energy density parameters, deceleration parameters and EOS (equation of state) parameters of Barrow holographic dark energy. The results show that the Barrow holographic dark energy in the DGP braneworld conforms to the current cosmic evolution rule, already achieved the universe main ingredients from matter to the transition of energy, and explains the problem of cosmic acceleration. Further, in order to distinguish between the model and Λ CDM model, this paper also geometrically diagnoses the model with the two ways of Statefinder hierarchy and Om (z). From their respective evolution image you can see, these two kinds of diagnosis methods can not only distinguish different from Λ CDM model, but also can intuitively reflect the coupling parameters that can significantly affect the dark energy model. [ABSTRACT FROM AUTHOR]

In this paper, we study a homogeneous and isotropic flat Friedmann–Robertson–Walker (FRW) universe in Rastall gravity, in which there exist the components of radiation and dust. That is to say, the density of fluid ρ γ satisfies the barotropic equation of state p γ = (γ − 1) ρ γ , where γ = 4 / 3 and 1 , and the equation of state w = γ − 1. We derive the modified Friedmann equations, and the effective equation of state w ̃ in this universe model. For the dust-dominated case, the effective equation of state w ̃ is described by λ − 1 3 λ − 1 , where λ is the Rastall parameter. As 1 3 < λ < 2 3 , we have w ̃ < − 1 3 which means an accelerated expansion of the universe occurs. Along with the conditions for the convergent modified Friedmann equations and the positive density of dust, the Rastall parameter λ should be in the range of (1 2 , 2 3). In other words, the various w ̃ for 1 2 < λ < 2 3 correspond to those of quintessence with the general barotropic equation of state (γ = 1). For the general case, the Rastall universe full of radiation and dust, the expression of w ̃ is complicated involving the Rastall parameter, the density of radiation and the density of dust. As the ratio of the densities of dust and radiation is smaller than 2 − 3 λ 2 (2 λ − 1) , w ̃ is less than − 1 3 . Moreover, to keep the density of dust positive, the Rastall parameter should be restricted in (1 2 , 2 3) too. By the numerical calculation, we find that w ̃ from 1 3 decreases as N (N ≡ l n a (t)) increases. And w ̃ for different λ ∈ (1 2 , 2 3) ultimately tend to λ − 1 3 λ − 1 , the value of which are in the range of (− 1 , − 1 3). Obviously, the expansion of the cosmology filled with radiation and dust or only dust in Rastall gravity (1 2 < λ < 2 3) accelerates without any "exotic" energy whose equation of state w < − 1 3 . [ABSTRACT FROM AUTHOR]

This paper investigates the static spherically symmetric vacuum solutions of Brans–Dicke Theory of Gravity. In this paper, we systematically derive the static spherically symmetric solutions by starting with the general static spherically symmetric anzats, discovering the nonzero Christoffel symbols, nonzero Ricci tensor components and the Ricci Scalar. These results allow us to rewrite the four Brans–Dicke gravitational field equations explicitly in terms of the metric components, the scalar field and its scalar potential. This paper systematically explains and shows how to modify these linear second-order ordinary differential equations in order to be able to find the solution of the scalar field, the metric components and the scalar potential analytically. We successfully find the most general solution of the static spherically symmetric vacuum solutions of Brans–Dicke gravity and the well-known Schwarzschild solution is recovered as the simplest solution. [ABSTRACT FROM AUTHOR]

Lots of ready quantum private comparison (QPC) protocols usually only judge whether two users' data are equal, whereas the quantum private magnitude comparison (QPMC) protocol can compare the magnitude of two numbers, whose results are greater than, equal and less than. It is by announcing a comparison result of two bits in two data that the existent QPMC protocols determine the size relationships of the whole data. Although the announcement leaks no information to outside attackers, yet it alerts two participants to know each other's value of a certain bit. This is termed as bit leakage in this paper. In order to remedy this shortage, the paper proposes a novel QPMC protocol using a type of Bell state. The protocol is thoroughly analyzed, correct and secure. Also, it proves free of bit leakage. Additionally, because it is easier to implement because of the usage of a type of Bell state, it counts as a better alternative for QPMC. [ABSTRACT FROM AUTHOR]

Measurements for the expansion rate of the universe disagree. Indeed, local measurements suggest a higher value of the Hubble constant than those performed through the cosmic microwave background. This fact led to a very interesting debate within the scientific community. The paper is not devoted to give solutions to the problem of "Hubble tension". The aim of this paper is, on the contrary, to deduce the Ω 0 m h 2 cosmological parameter from a theoretical point of view, using only two experimental data: the temperature of CMB today and the temperature of photons near the decoupling time. [ABSTRACT FROM AUTHOR]

In this paper, we discuss the linearization of vector-spinor (spin-3/2) nonlinear supersymmetry (vsNLSUSY) transformations for both N = 1 and N -extended SUSY in flat spacetime based on the commutator algebra by using functionals (composites) of spin-3/2 Nambu–Goldstone (NG) fermions, which are expressed as simple products of powers of the spin-3/2 NG fermions and a fundamental determinant in the vsNLSUSY theory. We define basic component fields by means of those functionals in a linearized vsSUSY theory including spin-3/2 fields, general auxiliary ones and a D -term. The general forms of linear (rigid) vsSUSY transformations for the component fields are determined uniquely from the commutator-based linearization procedure. By considering appropriate recombinations of the functionals of the spin-3/2 NG fermions for N = 1 SUSY, we find that variations of the recombinations under the vsNLSUSY transformations include linear spin-1/2 SUSY ones of spin- (3 / 2 , 1) fields with U (1) gauge invariance. The spinorial gauge invariance of the Rarita–Schwinger action in the linearization process is also discussed together with the U (1) gauge invariance. [ABSTRACT FROM AUTHOR]

In recent years, a class of compact objects called gravastars have drawn immense interest as regular solutions to end state stellar collapse. Since the energy density involved in collapse process is expected to be high, it is a natural choice to study such compact objects in context of modified gravity theories which reduce to General Relativity (GR) in the low energy regime. We have already framed a model of gravastar in such a modified gravity framework involving extra dimensional Randall–Sundrum (RS) single brane gravity [R. Sengupta, S. Ghosh, S. Ray, B. Mishra and S. K. Tripathy, Phys. Rev. D 102, 024037 (2020)]. As a sequel in this paper, we substantially improve our previous model by choosing the Kuchowicz function as one of the metric potentials, which leads to many new interesting results and physical features from our analysis as discussed in this paper. Also, we provide essential additional stability checks on our gravastar model to investigate the possibility of any instability creeping in due to the higher-dimensional framework. Our present improved gravastar model is found to clear all the stability checks successfully. Very interestingly, the static spherically symmetric matter distributions are found to accommodate both classes of solutions obeying and violating the modified energy conditions on the RS brane as we find in this work. We can conclude from our analysis that the Kuchowicz metric potential is very effective for describing regular solutions to compact objects at substantially high energies on the three-brane. [ABSTRACT FROM AUTHOR]

Entanglement is an important resource for quantum technologies that allow us to go beyond the classical world. Quantum systems can be entangled in various ways. Also, the degree of entanglement between the subsystems of a quantum system can be calculated in different ways. In our recent paper [Prog. Theor. Exp. Phys. (2022)], we directly measure the three-tangle of a pure three-qubit quantum state. In this paper, we extend this method to pure N-qubit quantum states (N is any odd number greater than 1) by considering polynomial invariant of degree 4 as a measure of entanglement. In this algorithm, we use quantum gates and output probabilities to calculate polynomial invariant of degree 4. The importance of this method lies in the possibility of experimental implementation of quantum calculations in the language of quantum gates. [ABSTRACT FROM AUTHOR]

Superposition is one of unusual features in quantum mechanics. This paper investigates the properties of multi-component Schrödinger cat state, generated by amplitude dispersion. The geometrical imaginary of the multi-component Schrödinger cat state is studied, and the entropy of the geometrical imaginary is proposed. This entropy is inverse proportional to the amplitude of the initial coherent state in the large amplitude regime. Additionally, the superposition of the multi-component cat state can be vividly displayed by the Wigner function and the Pegg–Barnett phase operator. [ABSTRACT FROM AUTHOR]

The quantum adder is a vital arithmetic operation for quantum algorithms. However, the existing quantum floating-point adders only considered the case of two normal numbers. In this paper, we propose an enhanced quantum floating-point adder based on IEEE 754 standard. First, we divide quantum floating-point adders into four cases: the normal case, subnormal case, mixed case, and special case. Then, we propose a result-sign and mantissa-sign determining unit to avoid conversion from sign-magnitude to two complements. Moreover, we design a new quantum leading zero detector with the optimized T-depth and T-count. Comparison results reveal that the proposed floating-point adder has lower circuit width, T-depth, and T-count than the current works. [ABSTRACT FROM AUTHOR]

In this paper, we examine the potential strong coupling problem at early times in a bouncing cosmological model with "strong gravity in the past" (Jordan frame), which is conformally related to inflation (Einstein frame). From naive-dimensional analysis in the Jordan frame, one would conclude that the quantum strong coupling energy scale can be lower than the classical energy scale. However, from the Einstein frame prospective, this should not be the case. We illustrate this point by calculation in the Jordan frame which shows cancellations of the dangerous contributions in the tree level amplitude. [ABSTRACT FROM AUTHOR]

Inspired by high-energy physics and by considering standard gravity theory as the low-energy limit of quantum theory, the modification of general relativity as R+f(G) has been proposed. This paper is dedicated to investigating the cosmological model of modified Gauss–Bonnet gravity in four dimensions. General field equations for the four-dimensional Friedmann– Robertson–Walker metric are given in detail. Also, it is well known that Hubble parameter H(z) measurements are helpful for the inference of cosmological model parameters. We try to explain the MCMC statistical approach used to calculate Hubble’s parameter. The resulting form of H(z) was limited using Cosmic Chronometric data, Standard Candles SN Ia from Pantheon, and Baryon Acoustic Oscillations to obtain the best match values by using the regression equation. Finally, to examine the late-time dynamics of our Universe, the behavior of physical and kinematic variables like the deceleration parameter (q), State-finder parameters {r,s}, diagnostic parameter (Om(z)), equation of state parameter as well as the behavior of energy conditions versus redshift with the parameter values are presented. [ABSTRACT FROM AUTHOR]

In this paper, we investigate hypergeometric stringy corrections in the swampland program for rescaled gravity. Precisely, we study inflationary models from Gauss–Bonnet hypergeometric scalar couplings via the falsification scenario. We first derive generalized exponential potentials from such hypergeometric behaviors. Then, we examine certain selected scalar potentials by computing the relevant cosmological quantities using the slow-roll mechanism. Choosing specific points in the corresponding moduli space, we provide viable findings corroborated by Planck observational data and checked by the swampland criteria. [ABSTRACT FROM AUTHOR]

In [Phys. Rev. D 107, 104008 (2023)], we reported a novel exact closed-form solution which describes asymptotically flat spacetimes in pure ℛ2 gravity. The solution is Ricci scalar flat, viz. ℛ≡0 everywhere. Whereas any metric with a null Ricci scalar would trivially satisfy the ℛ2 vacuo field equation, ℛ(ℛμν−14gμνℛ)+gμν□ℛ−∇μ∇νℛ=0, in this paper, we shall show that our solution satisfies a “stronger” version of the ℛ2 vacuo field equation, viz. ℛμν−14gμνℛ+ℛ−1(gμν□ℛ−∇μ∇νℛ)=0, despite the term ℛ−1 being singular. Even though ℛ identically vanishes, for our solution, the combinations ℛ−1∇μ∇νℛ and ℛ−1□ℛ are free of singularity. This exceptional property sets our solution apart from the set of null-Ricci-scalar metrics and makes it a genuinely nontrivial solution. We further demonstrate that, as a member of a larger class of asymptotically de Sitter metrics, our solution is resilient against perturbations in the scalar curvature at largest distances, making it relevant for physical situations where the background deviates from asymptotic flatness. [ABSTRACT FROM AUTHOR]

In this paper, we reconsider the concept of bulk viscosity in Brans–Dicke theory to study accelerated expansion of the universe in a flat Friedmann–Robertson–Walker metric. In recent works on bulk viscosity in Brans–Dicke theory, the power-law form of Brans–Dicke scalar field has been taken to explain recent phase transition of the universe, however, power-law form confronts constant deceleration parameter problem. Therefore, we consider recently proposed well-motivated logarithmic form of Brans–Dicke scalar field to discuss bulk viscous model in Brans–Dicke theory. We obtain the values of deceleration parameter and equation of state parameter for the model, and plot their graphs against the redshift parameter z. The plots show that the model is able to explain the recent phase transition of the universe and equation of state parameter shows the behavior of dark energy. Further, we apply two important analysis, namely, w−w′ analysis and thermodynamic analysis to examine our model. The w−w′ analysis shows that our model belong to thawing region and shows similarities with quintessence model. All the trajectories start from the point w′=0 with different negative values of w having quintessence behavior. The thermodynamic analysis shows that the model satisfies generalized second law of thermodynamics. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the quantum entanglement induced by phase-space noncommutativity. Both the position–position and momentum–momentum noncommutativity are incorporated to study the entanglement properties of coordinate and momentum degrees of freedom under the shade of oscillators in noncommutative space. Exact solutions for the systems are obtained after the model is re-expressed in terms of canonical variables, by performing a particular Bopp’s shift to the noncommuting degrees of freedom. It is shown that the bipartite Gaussian state for an isotropic oscillator is always separable. To extend our study for the time-dependent system, we allow arbitrary time dependency on parameters. The time-dependent isotropic oscillator is solved with the Lewis–Riesenfeld invariant method. It turns out that even for arbitrary time-dependent scenarios, the separability property does not alter.We extend our study to the anisotropic oscillator, which provides an entangled state even for time-independent parameters. The Wigner quasi-probability distribution is constructed for a bipartite Gaussian state. The noise matrix (covariance matrix) is explicitly studied with the help of Wigner distribution. Simon’s separability criterion (generalized Peres–Horodecki criterion) has been employed to find the unique function of the (mass and frequency) parameters, for which the bipartite states are separable. In particular, we show that the mere inclusion of non-commutativity of phase-space is not sufficient to generate the entanglement, rather anisotropy is important at the same footing.We explore the experimental viability of our result through the computation of extractable work for the current situation. [ABSTRACT FROM AUTHOR]

In this paper, we delve into the cosmological assessments concerning the deceleration parameter q=κ−γH in the context of the Bianchi type-III cosmological model within the framework of the Saez–Ballester theory of gravitation. By postulating a proportional relationship between the shear scalar (σ) and the expansion scalar (θ), we derive solutions for the corresponding field equations. Additionally, we conduct an examination and evaluation of the model’s physical and kinematic parameters, including the jerk parameter and snap parameter, while also discussing the energy condition of the model. Through the depiction of graphical representations, we illustrate the variations of the cosmological parameters for specific sets of constants. [ABSTRACT FROM AUTHOR]

In this paper, we propose quantum mechanical operator formalism for Touchard polynomials whose generating function is Tn(x)=∂n∂λne(eλ−1)x|λ=0. That is replacing eλx by eλa†a, where a†a is the number operator, and using the method of integration within ordered product we find that (a†a)n is just the normal ordering form :Tn(a†a):. Then by virtue of the Weyl ordering form of quantum mechanical operator, we also introduce a new special polynomial whose generating function is Gn(x)=∂n∂λn2eλ+1exp[2xeλ−1eλ+1]|λ=0. With use of the Weyl ordering form of eλa†a, we prove (a†a)n=:Tn(a†a):=::Gn(a†a)::, where :::: denotes Weyl ordering. It seems that quantum mechancal operator formalism presents a new and simpler approach for generalizing Touchard polynomial theory. [ABSTRACT FROM AUTHOR]

The dynamical map represents a fundamental concept in quantum field theory, providing a solution of the field equations in the Fock space of asymptotic fields. In this paper, we show how to express the dynamical map of a scalar field in the language of quantum effective action. This grants us new insights into the study of topological defects in quantum field theory by showing a connection between the usual least-action principle and Umezawa’s boson transformation method. [ABSTRACT FROM AUTHOR]

In this paper, we study the evolution of Bianchi-I spacetimes within the framework of the Horndeski theory with G5=const./X. The spacetimes are filled a global unidirectional electromagnetic field interacting with a scalar field. We consider the minimal interaction and the non-minimal interaction by the law f2(ϕ)FμνFμν. The Horndeski theory allows anisotropy to grow over time, so the question arises of regulating the anisotropic level in this theory. Using the designer method, we build models in which the anisotropic level tends to a small value as the Universe expands. One of the results is a model with a anisotropic bounce. [ABSTRACT FROM AUTHOR]

Recently, the precise observations have yielded values for the neutrino mixing angles, denoted as θ12 and θ13. Therefore, constructing a neutrino mixing model capable of accurately reflecting these measurements is crucial. In this paper, we propose a novel neutrino mixing model similar to the trimaximal mixing model. Unlike the trimaximal model that falls short of concurrently replicating the best-fit values of θ12 and θ13, our proposed mixing model has the ability to simultaneously reproduce the best-fit values for both angles. [ABSTRACT FROM AUTHOR]

The aim of this paper is to investigate the dynamical behavior of a Carbon atom under the forces of the two fullerenes in the circular restricted three-body (CR3B) configuration with nanoscale. Here, we assume that the mass of a Carbon atom varies according to the Jeans law, and then with the use of Meshcherskii transformation, we determine the equations of motion and quasi-Jacobian integral. Then by the use of numerical values of the parameters, we investigate the potential surfaces, equilibrium points, regions of motion, Poincaré surfaces of sections, periodic orbits, basins of attraction and stability of the equilibrium points. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the properties of a five-dimensional Ricci-flat black hole within the framework of the Space–Time–Matter theory. By employing the Klein–Gordon equation, we derive the wave function equations for both the mass dimensional coordinate and the radial dimensional coordinate. We present the analytical solutions for the wave function on the mass dimensional coordinate under two distinct scenarios. Remarkably, we observe the absence of quantum effects on the mass dimensional coordinate, which aligns with the absence of a barrier in the wave function equation. For the radial component, we employ the B-spline method to numerically solve its wave function. Our findings reveal the existence of Hawking radiation between the event horizon and the cosmological horizon, with the transmission and reflection probabilities being determined by the presence of a barrier. Furthermore, we discover a significantly higher probability of particle detection near the cosmological horizon, while the probability near the event horizon approaches zero. [ABSTRACT FROM AUTHOR]

In this paper, we analyze the results for the ground state of a Klein–Gordon oscillator under gravitational effects in a topologically charged Ellis–Bronnikov wormhole derived recently. We show that the authors failed to truncate a power-series and, consequently, could not obtain the desired solution to a differential equation. For this reason, their analytical expression for the ground-state eigenvalue is incorrect, a fact that affects all the conclusions drawn by the authors for the physical problem. [ABSTRACT FROM AUTHOR]

This paper delves into the exploration of quantum resources within a two-qubit system composed of two 2-level atoms connected to distinct thermal baths. Various quantifiers are employed to evaluate different aspects of the system's quantum characteristics. Specifically, the ℓ 1 -norm and relative entropy of coherence ( ℓ 1 and r ) are utilized to gauge quantum coherence, while local quantum Fisher information (LQFI) is used to quantify non-classical correlations within the system. The findings suggest that the amount of quantum correlations and coherence decline as the spontaneous emission rate γ t and the mean thermal photon number n increase. However, it is observed that manipulating parameters defining the initial state of the two-level atoms system can enhance non-classical correlations and quantum coherence between the two atoms. Additionally, it is noted that these three key metrics entirely vanish in the asymptotic limit of time. Our research underscores the importance of precisely adjusting the parameters of the initial system state, which is prepared in an extended Werner-like state (EWL), to protect quantum resources shared between the two atoms from environmental influences. [ABSTRACT FROM AUTHOR]

In this paper, we investigate how the electromagnetic field influences the idea of complexity within the framework of squared gravity. The physical traits, including heat dissipation, charge, anisotropic pressure, energy density variations and correction components are found to be significant contributors of complexity in celestial objects. By employing Herrera's orthogonal splitting approach, scalar functions are obtained yielding a complexity factor that incorporates the crucial attributes of the self-gravitating system. Furthermore, we examine the dynamics of charged spherical configuration by considering homologous mode as the simplest evolutionary pattern. Our investigation includes complexity-free scenarios (dissipative/non-dissipative) with homologous constraints. Moreover, we explore the components that contribute toward complexity during the evolutionary process. We conclude that self-gravitating structures get more complex with the inclusion of extra curvature terms of squared gravity and charge. [ABSTRACT FROM AUTHOR]

In this paper, a channel-optimized quantum communication scheme with imperfect Bell states is being considered, based on quantum teleportation and error correction codes technology. In this scheme, a novel "combination code" technique is proposed to protect the pre-shared Bell states from storage errors and to safeguard the information-encoded states from noisy channels. Ultimately, it is revealed by Monte Carlo simulation results that the channel fidelity of the proposed channel-optimized quantum communication scheme with imperfect Bell states is significantly advantageous over standard quantum error-correcting code (QECC) and entanglement-assisted quantum error-correcting code (EAQECC) communication schemes. [ABSTRACT FROM AUTHOR]

General theory of relativity can be equivalently formulated on a flat spacetime associating a torsion-free affine connection of non-vanishing non-metricity scalar Q. In this paper, we present an extension of this, viz., the f (Q) theory of gravity, and explore the early evolution of the universe in the background of anisotropic Bianchi-I model. The f (Q) theory in the current setting through its geometric modification is quite successful in explaining the late time accelerated expansion. Here, we note that it accommodates latest released constraints on the inflationary parameters by Planck's collaboration group with excellent precession, but fails to produce a viable decelerated expansion in the radiation dominated era. [ABSTRACT FROM AUTHOR]

One of the key factors of space weather is solar flare activity, the monitoring and prediction of which is an important task of specialized dedicated groups of space experts and solar astronomers. Solar flare forecasts are based on identifying and detecting the so-called precursors, specific processes in solar activity events that occur before flares. Collecting data for space weather analysis and prediction comes down to several types of measurements performed by more than a dozen spacecraft. Ground-based observations and monitoring nowadays are becoming more or less complimentary. One of the reasons for this is the limitation of observation time with ground-based telescopes due to adverse Earth weather conditions. However, solar radio astronomy is immune to almost any weather activity, and the main question here is what new quality it can bring. Observational data accumulated in the 20th century show that solar radio bursts can be associated with flare activity. In addition, the existing network of solar radio telescopes is already well established. As an example, in this paper, we describe the possibilities of a fully steerable 32-meter radio telescope of Ventspils International Radio Astronomy Centre (VIRAC), Latvia, which can be useful for searching for new precursors of solar flares. [ABSTRACT FROM AUTHOR]

In this paper, we introduce and characterize a pseudo-generalized Ricci-recurrent spacetimes and produce an example to verify the existence of such a spacetime. Then we demonstrate that a conformally flat generalized Ricci-recurrent spacetime with certain condition is a pseudo quasi-Einstein spacetime. Besides, it is proved that a pseudo-generalized Ricci-recurrent generalized Robertson–Walker spacetime represents a perfect fluid spacetime. Lastly, we study the impact of this spacetime under f (ℛ , T 2) and f (ℛ ∗) gravity scenario and deduce several energy conditions. [ABSTRACT FROM AUTHOR]

In this paper, we present a new method for searching maximally eight-qubit entangled states. Using 8-tangle and phase parameter orthogonal arrays, we can easily search maximally eight-qubit entangled states and obtain two new forms of maximally entangled eight-qubit states. We find that 8-tangle equaling zero is a necessary condition of maximally eight-qubit entangled states. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the exact bound state solution of the Klein–Gordon equation for an energy-dependent Coulomb-like vector plus scalar potential energies. To the best of our knowledge, this problem is examined in literature with a constant and position dependent mass functions. As a novelty, we assume a mass-function that depends on energy and position and revisit the problem with the following cases: First, we examine the case where the mixed vector and scalar potential energy possess equal magnitude and equal sign as well as an opposite sign. Then, we study pure scalar and pure vector cases. In each case, we derive an analytic expression of the energy spectrum by employing the asymptotic iteration method. We obtain a nontrivial relation among the tuning parameters which lead the examined problem to a constant mass one. Finally, we calculate the energy spectrum by the Secant method and show that the corresponding unnormalized wave functions satisfy the boundary conditions. We conclude the paper with a comparison of the calculated energy spectra versus tuning parameters. [ABSTRACT FROM AUTHOR]

In this paper our focus is on exploring the Ricci solitons of the Kantowski–Sachs spacetime. All the obtained Ricci solitons are expanding only. Also in all the cases except one case, Ricci soliton manifolds are Einstein and hence the Ricci solitons are the trivial Ricci solitons. Only in one particular case the obtained Ricci soliton is non-Einstein and expanding. We have also shown that in some cases the obtained Ricci soliton vector fields are potential fields while in other cases they are not potential fields. [ABSTRACT FROM AUTHOR]

In this paper, we study various cosmological parameters and quantities in scalar–tensor gravity (STG) from inflation and swampland conjecture. Therefore, by selecting different models as power-law, exponential, and logarithmic in the framework of scalar–tensor theory, we obtain potential, tensor-to-scalar ratio, and the scalar spectral index. Next, we examine new constraints and compare the corresponding results with the latest observable data. Here, we take advantage of the obtained results and determine the compatibility or incompatibility of the corresponding model with the swampland conjectures. [ABSTRACT FROM AUTHOR]

In this paper, we consider inhomogeneous spherically symmetric models based on the Lemaître–Tolman–Bondi (LTB) metric, assuming as its source an interactive mixture of ordinary baryonic matter, cold dark matter and dark energy with a coupling term proportional to the addition of energy densities of both dark fluids. We reduce Einstein's field equations to a first-order seven-dimensional autonomous dynamical system of evolution equations and algebraic constraints. We study in detail the evolution of the energy density and spatial curvature profiles along the phase–space by means of two subspace projections: a three-dimensional projection associated with the solutions of the Friedman–Lemaître–Robertson–Walker metric (invariant subspace) and a four-dimensional projection describing the evolution of the inhomogeneous fluctuations. We also classify and study the critical points of the system in comparison with previous work on similar sources, as well as solving numerically the equations for initial energy density and curvature profiles that lead to a spherical bounce whose collapsing time we estimate appropriately. [ABSTRACT FROM AUTHOR]

In this paper, we study a CPT-even Lorentz-breaking extension of the scalar QED. For this theory, we calculate the one-loop lower-order contributions in the Lorentz-violating parameters to the two-point functions of scalar and gauge fields. We found that the two background tensors, coming from the two sectors (scalar and gauge) are mixed in the one-loop corrections both in finite and divergent parts. This shows that these two Lorentz-breaking terms cannot be studied in an isolated form. Besides, the results in the gauge sector are confirmed to be transversal. [ABSTRACT FROM AUTHOR]

In this paper, we consider topological gauge theories in three dimensions which are defined by metric independent lagrangians. It has been claimed that the functional integration necessarily depends nontrivially on the gauge-fixing metric. We demonstrate that the partition function and the mean values of the gauge invariant observables do not really depend on the gauge-fixing metric. [ABSTRACT FROM AUTHOR]

This paper reveals the future prospects of quantum algorithms in high energy physics (HEP). Particle identification, knowing their properties and characteristics is a challenging problem in experimental HEP. The key technique to solve these problems is pattern recognition, which is an important application of machine learning and unconditionally used for HEP problems. To execute pattern recognition task for track and vertex reconstruction, the particle physics community vastly use statistical machine learning methods. These methods vary from detector-to-detector geometry and magnetic field used in the experiment. Here, in this paper, we deliver the future possibilities for the lucid application of quantum computation and quantum machine learning in HEP, rather than focusing on deep mathematical structures of techniques arising in this domain. [ABSTRACT FROM AUTHOR]

In this paper, the complete discrimination system for the polynomial method is applied to solve the Wu–Zhang system, and all the possible exact solutions are obtained, these exact solutions can be applied to the exploration of nonlinear physical phenomena, the method in this paper is different from the existing literature studies on the Wu–Zhang equation. By taking different parameters, interesting graphs are plotted for all the obtained solutions. The results confirm that the proposed method is effective and can be used to solve a variety of nonlinear consistency time fractional partial differential equations. [ABSTRACT FROM AUTHOR]

In this paper, we consider the scalar mode of gravity as expressed by a conformal factor of the metric and present a model motivated by the Jordan–Brans–Dicke action. The reduced action provides a Lagrangian density in Minkowski space which exhibits a massive particle and an expanding spacetime through a mechanism which is similar to the Higgs mechanism. [ABSTRACT FROM AUTHOR]

In this work, we calculate the expression for the potential due to neutrino–(anti)neutrino forward scattering at low energies (E ≪ m Z 0 ) for ultra-relativistic massive neutrinos (E ≫ m ν) , a representative regime within astrophysical scenarios. There is a broadly used expression for this potential in the literature, which, however, lacks an explicit derivation from basic principles of quantum field theory. Therefore, this paper has an intention to guide the reader through the steps and concepts to derive this potential, trying to be clear and pedagogical. Moreover, we used a rigorous approach concerning the massive nature of the neutrinos, using massive quantized neutrino fields throughout the entire process, while the usual approach is to consider massless neutrino fields at the interaction. In this context, we explicitly show the validity of the massless neutrino fields approximation at the ultra-relativistic regime, as expected. As the last step, we connect the potential expression to the density matrix formalism, which is a usual framework for works considering neutrino–neutrino interactions. We also discuss some theoretical details through the paper such as the normal ordering of quantum operators and the implications of massive fields in the neutrino state at its production. [ABSTRACT FROM AUTHOR]

In this paper, we verify a method which allows to obtain the β -function of supersymmetric theories regularized by higher covariant derivatives by calculating only specially modified vacuum supergraphs. With the help of this method for a general renormalizable = 1 supersymmetric gauge theory, a part of the three-loop β -function depending on the Yukawa couplings is constructed in the general ξ -gauge. The result is written in the form of an integral of double total derivatives with respect to the loop momenta. It is demonstrated that all gauge-dependent terms cancel each other in agreement with the general statements. The result in the Feynman gauge (found earlier) coincides with the one obtained by the standard technique which requires to calculate the sum of superdiagrams with two external gauge lines. This fact confirms the correctness of the considered method by a highly nontrivial multiloop calculation. [ABSTRACT FROM AUTHOR]

In this paper, the energy density of plane gravitational wave is studied by using Einstein and Møller's prescription of energy–momentum pseudotensors. The linearly polarized plane gravitational wave solution of Einstein field equation, which has been defined by Bondi et al., is represented by four kinds of different coordinates. The energy distributions of gravitational wave solution in Einstein and Møller's prescription are obtained. Particularly, the energy component is zero in null coordinates. [ABSTRACT FROM AUTHOR]

At zero temperature and finite chemical potential, the gap equation of cold dense quark matter under external magnetic field is studied with NJL model in the mean-field approximation. By introducing new methods, it is found that the Nambu phase has sophisticated structures which have not been studied before. As a consequence, the phase diagram is expanded and divided into five areas, in each area the condensate has unique behaviors with chemical potential varying. Furthermore, the expanded phase diagram is used to predict the order of phase transition between the Nambu phase and the Wigner phase, it can also be used to explain the relations of dynamical mass and chemical potential. Meanwhile, the metastable states and cascade effect of dynamical mass are studied in this paper. [ABSTRACT FROM AUTHOR]