International Journal of Modern Physics A

We present a new mechanism for solving the fermionic masses and mixing hierarchies of the Standard Model through a minimal symmetry ${{𝒵}}_2\times {{𝒵}}_5$. The mechanism is also capable of explaining the neutrino masses and mixing parameters. The phenomenological bounds arising from kaon mixing are also derived on the parameter space of the model.

Using T-duality, we will argue that a zero point length exists in the low-energy effective field theory of string theory on compactified extra dimensions. Furthermore, if we neglect all the oscillator modes, this zero point length would modify low quantum mechanical systems. As this zero length is fixed geometrically, it is important to analyze how it modifies purely quantum mechanical effects. Thus, we will analyze its effects on quantum erasers, because they are based on quantum effects like entanglement. It will be observed that the behavior of these quantum erasers gets modified by this zero point length. As the zero point length is fixed by the radius of compactification, we argue that these results demonstrate a deeper connection between geometry and quantum effects.

The fact that certain “extraordinary” probabilistic phenomena — in particular, macroscopic violations of the second law of thermodynamics — have never been observed to occur can be accounted for by taking hard preclusion as a basic physical law, i.e. precluding from existence events corresponding to very small but nonzero values of quantum-mechanical weight. This approach is not consistent with the usual ontology of the Everett interpretation, in which outcomes correspond to branches of the state vector, but can be successfully implemented using a Heisenberg-picture-based ontology in which outcomes are encoded in transformations of operators. Hard preclusion can provide an explanation for biological evolution, which can in turn explain our subjective experiences of, and reactions to, “ordinary” probabilistic phenomena, and the compatibility of those experiences and reactions with what we conventionally take to be objective probabilities arising from physical laws.

In this paper, we present a model independent analysis of Leptonic CP violation for some well-known mixing scenarios. In particular, we considered modified schemes for bimaximal (BM), democratic (DC), hexagonal (HG) and tribimaximal (TBM) mixing for our numerical investigation. These model independent corrections to mixing matrices are parametrized in terms of complex rotation matrices $(U)$ with related modified PMNS matrix of the forms $\left(U_{ij}^l\cdot V_M,V_M\cdot U_{ij}^r\right)$ where $U_{ij}^{l,r}$ is a complex rotation in $ij$ sector and $V_M$ is unperturbed mixing scheme. We present generic formulae for mixing angles, Dirac CP phase $({\delta }_{\mathrm{\text{CP}}})$ and Jarlskog invariant $(J_{\mathrm{\text{CP}}})$ in terms of correction parameters. The parameter space of each modified mixing case is scanned for fitting neutrino mixing angles using ${\chi }^2$ approach and the corresponding predictions for Leptonic CP phase $({\delta }_{\mathrm{\text{CP}}})$ and Jarlskog invariant $(J_{\mathrm{\text{CP}}})$ has been evaluated from allowed parameter space. The obtained ranges are reported for all viable cases.

This paper deals with some wormhole solutions which are obtained by taking two different shape functions along with zero tidal force. For obtaining wormhole solutions, anisotropic fluid and a equation of state $p_t=-\frac{a}{\rho }$ related by Chaplygin gas are considered, where $\rho$ is the energy density, $p_t$ is tangential pressure and $a$ is positive constant. Energy conditions are examined for two different models, and it is found that major energy conditions are satisfied in a region.

In this paper, we solve the Dirac Equation in curved space–time, modified by the generalized uncertainty principle, in the presence of an electromagnetic field. Using this, we study the tunneling of $1/2$-spin fermions from Kerr–Newman black hole. Corrections to the Hawking temperature and entropy of the black hole due to quantum gravity effects are also discussed.

In this paper, we study anomalous hydrodynamics with a dyonic charge. We show that the local second law of thermodynamics constrains the structure of the anomaly in addition to the structure of the hydrodynamic constitutive equations. In particular, we show that not only the usual $E\cdot B$ term but also $E^2-B^2$ term should be present in the anomaly with a specific coefficient for the local entropy production to be positive definite.

In this work, we propose a model of noncommutative cosmology through the deformation of minisuperspace. We focus on an exponentially potential with a homogeneous scalar field minimally coupled to gravity in the spatially flat universe. To process, we use a particular case of noncommutativity by making a deformation of space coordinates only. Then, we compare results in both the commutative model and the noncommutative one.

We study the effect of the scotogenic dark matter on the primordial black holes (PBHs) and vice versa. We show that if the PBHs evaporate in the radiation dominated era, the upper limit of the initial mass of the PBHs $M_{\mathrm{\text{in}}}$ should be constrained as $10^4\lesssim M_{\mathrm{\text{in}}}/M_{\mathrm{\text{Pl}}}\lesssim 10^{10}$ for ${𝒪}(1)$ TeV scotogenic dark matter $({𝒪}(1)$ TeV is the most appropriate energy scale in the scotogenic model). On the other hand, if the PBHs evaporate in the PBH dominated era, a quite heavy scotogenic dark matter ($m_{\mathrm{\text{DM}}}\gtrsim 10^9$ GeV) for $M_{\mathrm{\text{in}}}/M_{\mathrm{\text{Pl}}}\sim 10^{13}$ may be allowed.

We consider the classical three-body system with $d$ degrees of freedom $(d>1)$ at zero total angular momentum. The study is restricted to potentials $V$ that depend solely on relative (mutual) distances $r_{ij}=|r_i-r_j|$ between bodies. Following the proposal by J. L. Lagrange, in the center-of-mass frame we introduce the relative distances (complemented by angles) as generalized coordinates and show that the kinetic energy does not depend on $d$, confirming results by Murnaghan (1936) at $d=2$ and van Kampen–Wintner (1937) at $d=3$, where it corresponds to a 3D solid body. Realizing ${\mathbb{Z}}_2$-symmetry $(r_{ij}\to -r_{ij})$, we introduce new variables ${\rho }_{ij}=r_{ij}^2$, which allows us to make the tensor of inertia nonsingular for binary collisions. In these variables the kinetic energy is a polynomial function in the $\rho$-phase space. The three-body positions form a triangle (of interaction) and the kinetic energy is ${{𝒮}}_3$-permutationally invariant with respect to interchange of body positions and masses (as well as with respect to interchange of edges of the triangle and masses). For equal masses, we use lowest order symmetric polynomial invariants of ${\mathbb{Z}}_2^{\otimes 3}\oplus {{𝒮}}_3$ to define new generalized coordinates, they are called the geometrical variables. Two of them of the lowest order (sum of squares of sides of triangle and square of the area) are called volume variables. It is shown that for potentials which depend on geometrical variables only (i) and those which depend on mass-dependent volume variables alone (ii), the Hamilton’s equations of motion can be considered as being relatively simple.

We study three examples in some detail: (I) three-body Newton gravity in $d=3$, (II) three-body choreography in $d=2$ on the algebraic lemniscate by Fujiwara et al., where the problem becomes one-dimensional in the geometrical variables and (III) the (an)harmonic oscillator.