Modern Physics Letters A

In the framework of anomaly free $U{(1)}_{L_{\mu }-L_{\tau }}$ model, singlet scalar field with nonzero $L_{\mu }-L_{\tau }$ charge gives rise to massive gauge boson $(Z_{\mu \tau })$ through spontaneous symmetry breaking. $Z_{\mu \tau }$ leads to one loop contribution to the muon anomalous magnetic moment. These scalar fields may, also, appear in the structure of right-handed neutrino mass matrix, thus, connecting the possible explanation of muon $(g-2)$ and low-energy neutrino phenomenology through vevs associated with the scalar fields. In this work, we consider textures of inverse neutrino mass matrix $(M_{\nu }^{-1})$ wherein any two elements of the mass matrix are zero. In this ansatz, with Dirac neutrino mass matrix diagonal, the zero(s) of right-handed Majorana neutrino mass matrix correspond to zero(s) in the low-energy effective neutrino mass matrix (within Type-I seesaw). We have realized two such textures of $M_{\nu }^{-1}$ accommodating the muon $(g-2)$ and low-energy neutrino phenomenology. The requirement of successful explanation of muon $(g-2)$, further, constrains the allowed parameter space of the model and results in sharp correlations amongst neutrino mixing angles and CP invariants. The model explains muon $(g-2)$ for $M_{Z_{\mu \tau }}$ in the range (0.035–0.100 GeV) and $g_{\mu \tau }\approx {𝒪}(10^{-4})$ which is found to be consistent with constraints coming from the current experiments CCFR, COHERENT, BABAR while being within sensitivities of future experiments such as NA62 and NA64.

Neutrino physics is one of the most active fields of research with important implications for particle physics, cosmology and astrophysics. On the other hand, motivated by some theories including string theory, formulation of physical theories in more than four spacetime dimensions has been the subject of increasing attention in recent years. Interaction of neutrinos with gravitational fields is one of the interesting phenomena which can lead to transition between different helicity states (spin oscillations). We study neutrino spin oscillations in Schwarzschild and RN backgrounds in higher-dimensional gravitational fields. We calculate the transition probability as a function of time and also study the dependence of the oscillation frequency on the orbital radius. The results help us to better understand the behavior of gravity and neutrinos in higher dimensions.

In this paper, we discuss the ultraviolet sector of (3 + 1)-dimensional Lifshitz-type anisotropic higher derivative scalar, fermion and gauge field theories, with anisotropy exponent $z=3$ and with explicit breaking of Lorentz symmetry. By discarding from the action of all momentum-dependent vertex operators, which is essential to avoid phenomenologically unacceptable deformations of the light cone, we find that renormalizable scalar self-interaction and Yukawa-like couplings are, in general, asymptotically free. However, the requirement of cancelling momentum-dependent vertex operators is incompatible with gauge symmetry and, therefore, for this kind of theories, gauge symmetry as well as Lorentz symmetry are recovered only as emergent properties below some energy scale $M$, that must be constrained from experiments. The quantum corrections to the scalar mass and their impact on the hierarchy problem are also analyzed.

This work deals with the newly approached extended $f(P)$ cubic gravity in a cosmological background where $P$ denotes the cubic gravity. Here, we peruse the cosmological nature of the different types of dark energy candidates in the framework of $f(P)$ gravity. Next, we study the reconstruction scenario of $f(P)$ gravity model according to ordinary holographic dark energy, ordinary new agegraphic dark energy, entropy-corrected holographic dark energy in power-law and logarithmic versions and entropy-corrected new agegraphic dark energy in power-law and logarithmic versions with two classes of the scale factor. We derive different forms of the unknown function $f(P)$ in the context of these dark energy candidates. By the trajectories of the EoS parameter $w_P$, all models give evidence of their candidature for the explanation of the phantom regime and also the quintessence regime in the late stage of the universe. Also, the stability condition ensures that our reconstructed models are classically stable.

By consideration of an Einstein-dilaton nonlinear charged gravitating system, it has been shown that this theory is confronted with the problem of indeterminacy. It means that the number of independent differential equations is one less than the number of unknowns. To overcome this problem, the power-law and exponential ansatz functions have been used, separately. Through solving the field equations, in the presence of a Coulomb-like electric field, it has been found that this theory includes two novel classes of charged black holes (BHs) with unusual asymptotic behavior, for each ansatz. It has been found that, under some circumstances, both of the ansatz functions lead to the same results. The novel exact solutions show BHs with one horizon, two horizons and without horizon. Using a Smarr-type mass formula, the validity of the first law of BH thermodynamics (FLT) has been proved, after calculating the thermodynamic and conserved quantities. Making use of thermodynamical and geometrical approaches, thermal stability of the BHs has been analyzed. Results of the aforementioned methods have been compared by use of the plots.

In this paper, we have provided a new family of solutions to Einstein–Maxwell field equations of charged spherically symmetric anisotropic matter distribution, related to the description of strange stars, in the background of Rastall-Rainbow gravity. We have constructed the field equations along with cosmological constant $(\mathrm{\Lambda })$ and quintessence dark energy described by the equation of state $w_q$ satisfying the range $-1<w_q<-1/3$. We have solved the field equations by the proper choice of some relations like radial pressure with energy density and tangential pressures with the energy density and also a useful form of energy density. Next, we have discussed about the smooth connection between the interior spherically symmetric spacetime and the exterior Reissner–Nordstrom-de Sitter spacetime. To demonstrate the physical viability of our considered model, we have discussed a detailed physical analysis of different parameters analytically and graphically. Our whole graphical analysis has been performed for three compact stars like VelaX-1, SAXJ1808.4-3658 and 4U1820-30 in the context of our solutions. With the help of various suitable conditions for stability, we have examined the stability of our model by checking the radial and tangential sound speeds and the adiabatic index values.

Studying quantum entanglement in systems of indistinguishable particles, in particular anyons, poses subtle challenges. Here, we investigate a model of one-dimensional anyons defined by a generalized algebra. This algebra has the special property that fermions in this model are composites of anyons. A Hubbard-like Hamiltonian is considered that allows hopping between nearest neighbor sites not just for the fundamental anyons, but for the fermionic anyon composites. Some interesting results regarding the quantum entanglement of these particles are obtained.