Modern Physics Letters A

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.

In this paper, we study the thermodynamical and mathematical consistencies for a non-singular early-time viscous cosmological model known as soft-Big Bang, which was previously found in [N. Cruz, E. González and J. Jovel, Phys. Rev. D 105, 024047 (2022)]. This model represents a flat homogeneous and isotropic universe filled with a dissipative radiation fluid and a cosmological constant $\mathrm{\Lambda }$, which is small but not negligible, in the framework of Eckart’s theory. In particular, we discuss the capability of the solution in the fulfillment of the three following conditions: (i) the near equilibrium condition, which is assumed in Eckart’s theory of non-perfect fluids, (ii) the mathematical stability of the solution under small perturbations, and (iii) the positiveness of the entropy production. We have found that this viscous model can describe the radiation domination era of the $\mathrm{\Lambda }$CDM model and, at the same time, fulfill the three conditions mentioned by the fulfillment of a single constraint on the bulk viscous coefficient ${\xi }_0$, finding also that this non-singular model has a positive energy density in the infinity past which is infinity hotter with a constant entropy.

In this paper, we discuss the tunneling of scalar particles near the event horizon of stationary and nonstationary Kerr–de Sitter black hole using Lorentz violation theory in curved space time. The modified form of Hamilton–Jacobi equation is derived from the Klein–Gordon equation by applying Lorentz violation theory. The Hawking temperatures derived from stationary and nonstationary Kerr–de Sitter black holes are modified due to Lorentz violation theory. It is noted that the change in Bekenstein–Hawking entropy and modified Hawking temperatures of stationary and nonstationary Kerr–de Sitter black hole not only depends on the black hole parameters but also on ether-like vectors ${\mathrm{\text{u}}}^{\alpha }$.

The CDF-II collaboration’s recent high-precision measurement of $W$-boson mass indicates new physics contribution(s) beyond the Standard Model. We investigate the possibility of the well-known canonical Scotogenic model to explain the CDF-II measurement. The Scotogenic model is a popular scenario beyond the Standard Model that induces neutrino masses at the one-loop level and includes a viable dark matter candidate, either scalar or fermionic. For both scalar and fermionic dark matter possibilities, we simultaneously examine the constraints coming from (a) neutrino mass, oscillation, neutrinoless double beta decay and lepton flavor violation experiments, (b) from LEP and LHC, (c) from dark matter relic density and direct detection experiments, (d) from the oblique $S,T,U$ parameter values consistent with CDF-II $W$-boson measurement. We demonstrate that the new CDF-II measurement rules out the feasible parameter space of the scalar dark matter in the high mass regions ($m_{{\eta }_R}\gtrsim 500\mathrm{\text{GeV}}$), while still allowing the intermediate mass regions $54\mathrm{\text{GeV}}\lesssim m_{{\eta }_R}\lesssim 76\mathrm{\text{GeV}}$. We also showed that the fermionic dark matter candidate in the canonical Scotogenic model, in the range $M_{N_1}\lesssim 500\mathrm{\text{GeV}}$, can simultaneously explain all the aforementioned issues. Furthermore, we investigated how the recent findings from ATLAS 2023 impact this study.

This work deals with the two fluid Bianchi type-V cosmological models consisting of matter and radiating source in the $f(R,T)$ theory of gravity studied by Harko et al. [Phys. Rev. D 84, 024020 (2011)]. In this paper, we developed a new idea about $f(R,T)$ gravity with the help of two fluids: one fluid is matter field modeling material content of the Universe and other fluid is radiation field modeling the cosmic microwave background (CMB). We have determined the solution of the two fluid gravitational field equations with the systematic structure in $f(R,T)$ gravity. Here, we have deliberated four types of universe such as dust universe, radiation universe, hard universe and Zel’dovich universe and also extended our work to observe the big rip and big bang singularity. We have also tested the cosmological parameters.

Classical forgery attacks against Offset Two-round (OTR) structures require some harsh conditions, such as some plaintext and ciphertext pairs need to be known, and the success probability is not too high. To solve these problems, a quantum forgery attack on OTR structure using Simon’s algorithm is proposed. The attacker intercepts the ciphertext-tag pair $(C,T)$ between the sender and receiver, while Simon’s algorithm is used to find the period of the tag generation function in OTR, then we can successfully forge new ciphertext $C^{\prime }$ ($C^{\prime }\ne C$) for intercepted tag $T$. For a variant of OTR structure (Prøst-OTR-Even-Mansour structure), a universal forgery attack, in which it is easy to generate the correct tag of any given message if the attacker is allowed to change a single block in it, is proposed. It first obtains the secret parameter $L$ using Simon’s algorithm, then the secret parameter $L$ is used to find the keys $k_1$ and $k_2$, so that an attacker can forge the changed messages. It only needs several plaintext blocks to help obtain the keys to forge any messages. Performance analysis shows that the query complexity of our attack is $O(n)$, and its success probability is very close to 1.

A spatially homogenous and anisotropic locally rotationally symmetric (LRS) Bianchi type-I space-time is considered in the presence of a massive scalar field containing domain walls in the framework of the $f(R,T)$ gravity proposed by Harko et al. [Phys. Rev. D 84, 024020, (2011)]. Solving the field equations of the model using a relation between metric potentials and power law between the scalar field and average scale factor of the model, an anisotropic cosmological model with massive scalar fields and domain walls in $f(R,T)$ theory is presented. These conditions result in a model solution that provides a dynamic deceleration parameter. The model’s geometrical and physical properties are also examined. The universe exhibits a smooth transition from its early decelerated phase to its current accelerated phase, as shown by the study of the deceleration parameter. The statefinder plane corresponds to the Chaplygin gas era and the model finally approaches $\mathrm{\Lambda }$CDM model.

In this paper, we argue that the results shown in [Mod. Phys. Lett. A 34, 1950319 (2019)] are not correct. The truncation of the Frobenius method only yields some particular bound states from which one cannot derive any sound physical conclusion. The existence of allowed model parameters is an artifact of such procedure. Besides, the authors failed to obtain most of the solutions given by the truncation of the Frobenius series as well as their connection with the actual eigenvalues of the problem.