arXiv subjects

J. Juan Rosales

Publications and source records attributed to J. Juan Rosales.

5 recordsLinked to original sources

arXiv2024

Non commutative classical and Quantum fractionary Cosmology: Anisotropic Bianchi Type I case

In this work, we will explore the effects of non-commutativity in fractional classical and quantum schemes using the anisotropicc Bianchi Type I cosmological model coupled to a scalar field in the K-essence formalism. We introduce non-commutative variables considering that all minisuperspace variables $q^i_{nc}$ do not commute, so the symplectic structure was modified, resulting in some changes with respect to the traditional formalism. In the quantum regime, the probability density presents a new structure in the scalar field corresponding to the value of the non-commutative parameter.

gr-qc↗

arXiv2024

Non commutative classical and Quantum fractionary Cosmology: FRW case

In this work we shall explore the effects of non commutativity in fractional classical and quantum schemes using the flat Friedmmann-Robertson-Walker (FRW) cosmological model coupled to a scalar field in the K-essence formalism. In previous work we have obtained the commutative solutions in both regimes into the fractional framework. Here we introduce noncommutative variables, considering that all minisuperspace variables $\rm q^i_{nc}$ do not commute, so the symplectic structure was modified. In the quantum regime, the probability density presents new structure in the scalar field corresponding to the value of the non-commutative parameter, in the sense that this probability density undergoes a shift back to the direction of the scale factor, causing classical evolution to arise earlier than in the commutative world.

gr-qc↗

arXiv2023

Anisotropic fractional cosmology: K-essence theory

In the particular configuration of the scalar field K-essence in the Wheeler-DeWitt quantum equation, for some age in the Bianchi type I anisotropic cosmological model, a fractional differential equation for the scalar field arises naturally. The order of the fractional differential equation is $β=\frac{2α}{2α- 1}$. This fractional equation belongs to different intervals, depending on the value of the barotropic parameter; when $ω_{X} \in [0,1]$, the order belongs to the interval $1\leq β\leq 2$, and when $ω_{X}\in[-1,0)$, the order belongs to the interval $0< β\leq 1$. In the quantum scheme, we introduce the factor ordering problem in the variables $(Ω,ϕ)$ and its corresponding momenta $(Π_Ω, Π_ϕ)$, obtaining a linear fractional differential equation with variable coefficients in the scalar field equation, then the solution is found using a fractional power series expansion. The corresponding quantum solutions are also given. We found the classical solution in the usual gauge N obtained in the Hamiltonian formalism and without a gauge. In the last case, the general solution is presented in a transformed time $T(τ)$, however in the dust era we found a closed solution in the gauge time $τ$. Keywords: Fractional derivative, Fractional Quantum Cosmology; K-essence formalism; Classical and Quantum exact solutions.

gr-qc↗

arXiv2023

Quantum fractionary cosmology: K-essence theory

Using a particular form of the quantum K-essence scalar field, we show that in the quantum formalism, a fractional differential equation in the scalar field variable, for some epochs in the Friedmann-Lemaître-Robertson-Walker (FLRW) model (radiation and inflation-like epochs, for example), appears naturally. In the classical analysis, the kinetic energy of scalar fields can falsify the standard matter in the sense that we obtain the time behavior for the scale factor in all scenarios of our Universe by using the Hamiltonian formalism, where the results are analogous to those obtained by an algebraic procedure in the Einstein field equations with standard matter. In the case of the quantum Wheeler-DeWitt (WDW) equation for the scalar field $ϕ$, a fractional differential equation of order $β=\frac{2α}{2α-1}$ is obtained. This fractional equation belongs to different intervals, depending on the value of the barotropic parameter; that is to say, when $ ω_X \in [0,1]$, the order belongs to the interval $1\leq β\leq 2$, and when $ ω_X \in [-1,0)$, the order belongs to the interval $0< β\leq 1$. The corresponding quantum solutions are also given.

gr-qc↗

arXiv1999

N=4 Supersymmetric Multidimensional Quantum Mechanics, Partial SUSY Breaking and Superconformal Quantum Mechanics

The multidimensional N=4 supersymmetric quantum mechanics (SUSY QM) is constructed using the superfield approach. As a result, the component form of the classical and quantum Lagrangian and Hamiltonian is obtained. In the considered SUSY QM both classical and quantum N=4 algebras include central charges, and this opens various possibilities for partial supersymmetry breaking. It is shown that quantum mechanical models with one quarter, one half and three quarters of unbroken(broken) supersymmetries can exist in the framework of the multidimensional N=4 SUSY QM, while the one-dimensional N=4 SUSY QM, constructed earlier, admits only one half or total supersymmetry breakdown. We illustrate the constructed general formalism, as well as all possible cases of the partial SUSY breaking taking as an example a direct multidimensional generalization of the one-dimensional N=4 superconformal quantum mechanical model. Some open questions and possible applications of the constructed multidimensional N=4 SUSY QM to the known exactly integrable systems and problems of quantum cosmology are briefly discussed.

hep-th↗