Nuclear Physics B最新文献

This paper, as a continuation of our previous investigation [Nucl. Phys. B 1005 (2024) 116582] aims to study the glassy random matrices with quenched Wigner disorder. In this previous work, we have constructed a renormalization group based on the effective deterministic kinetic spectrum emerging from large N limit, and we extended approximate solutions using standard vertex expansion, at the leading order of the derivative expansion. Now in the following work, by introducing the non-trivial Ward identities which come from the ${\left(U\right(N\left)\right)}^{\times 2}$ symmetry broken of the effective kinetic action, we provide in the deep IR the explicit solution of the functional renormalization group for a model with quartic coupling by solving the Hierarchy to all orders in the local sector, which in particular imply the vanishing of the anomalous dimension. The numerical investigations confirm the first-order phase transition discovered in the vertex expansion framework, both in the active and passive schemes. Finally, we extend the discussion to hermitian matrices.

This study investigates the application of wave functions to explore various solutions of the Klein-Gordon and Schrödinger equations within the framework of Lovelock gravity. We also present the derived Smarr formula from the topological density. The Klein-Gordon solution leads to the Wheeler-de Witt Hamiltonian and quasinormal modes, and we demonstrate the connection between the potential and the black hole temperature within the Schwarzschild limit. Additionally, we discuss different solutions of the Schrödinger equation, with one solution highlighting the influence of the Airy solution on the wave function's evolution over time.

We investigate Klein-Gordon (KG) oscillators in a Gödel-type Som-Raychaudhuri spacetime in a mixed magnetic field (given by the vector potential $A_{\mu }=(0,0,A_{\phi },0)$, with $A_{\phi }=B_1{r}^2/2+B_{2}r$). The resulting KG equation takes a Schrödinger-like form (with an oscillator plus a linear plus a Coulomb-like interactions potential) that admits a solution in the form of biconfluent Heun functions/series $H_B(\alpha ,\beta ,\gamma ,\delta ,z)$. The usual power series expansion of which is truncated to a polynomial of order $n_r+1=n\ge 1$ through the usual condition $\gamma =2(n_r+1)+\alpha$. However, we use the very recent recipe suggested by Mustafa [42] as an alternative parametric condition/correlation. i.e., $\delta =-\beta (2n_r+\alpha +3)$, to facilitate conditional exact solvability of the problem. We discuss and report the effects of the mixed magnetic field as well as the effects of the Gödel-type SR-spacetime background on the KG-oscillators' spectroscopic structure.

We show analytically that there exist compact stellar objects akin to neutron stars whose radius is smaller than the Schwarzschild radius defined by Arnowitt-Deser-Misner (ADM) mass. The radius of the compact object is defined by the radius where the energy density and the pressure of ordinary matter vanish, while clouds of scalar(s) can extend beyond this radius – a situation that is often encountered in modified gravity theories, like $F\left(R\right)$ gravity and the scalar–Einstein–Gauss-Bonnet gravity. The clouds of scalar mode(s) give additional contributions to the ADM mass and as a result, the corresponding Schwarzschild radius given by the ADM mass can be larger than that of the compact object.

It is known that for the Heisenberg XXZ spin - $\frac{1}{2}$ chain in the critical regime, the scaling limit of the vacuum Bethe roots yields an infinite set of numbers that coincide with the energy spectrum of the quantum mechanical 3D anharmonic oscillator. The discovery of this curious relation, among others, gave rise to the approach referred to as the ODE/IQFT (or ODE/IM) correspondence. Here we consider a multiparametric generalization of the Heisenberg spin chain, which is associated with the inhomogeneous six-vertex model. When quasi-periodic boundary conditions are imposed the lattice system may be explored within the Bethe Ansatz technique. We argue that for the critical spin chain, with a properly formulated scaling limit, the scaled Bethe roots for the ground state are described by second order differential equations, which are multi-parametric generalizations of the Schrödinger equation for the anharmonic oscillator.

The left-right symmetric models (LRSM) generally include type-I and type-II induced seesaw masses as a hybrid mass for the light-active neutrinos. Assuming a particular form of Dirac-type coupling, the Majorana-type coupling present in the seesaw mass formula can be expressed in terms of low-energy neutrino oscillation observables and vacuum expectation values (vevs) of the scalar fields present in the model. The Majorana-type coupling thus admits eight different solutions by considering whether the type-I and type-II terms dominate the light neutrino mass. We study the role of all eight solutions in the lepton number violating neutrinoless double beta decay ($0\nu \beta \beta$) process. In LRSM, the right-handed neutrinos, triplet scalars, and gauge bosons of the left and right sectors act as mediators of new contributions to the $0\nu \beta \beta$ process. As a result, the effective mass of electron neutrino appearing in the decay width would be a function of $v_R$ (vev of the Higgs triplet of the right sector) along with other parameters of the model, through the masses of the new contributions. The energy scale, $v_R$ can be considered as the new physics scale which allows exploring physics beyond the Standard Model. Considering the present and future sensitivity of searches of $0\nu \beta \beta$, we study the role of eight different solutions of the Majorana coupling matrix. In our study, the inverted hierarchy of light neutrino masses is disfavored for all solutions keeping future sensitivity of effective mass in the picture, if the lightest mass of active neutrinos is below 0.001 eV. Also, our study shows a possibility of new physics contributions saturating the experimental bound on effective mass for $v_R$ in the range of 10 TeV for two particular solutions of the Majorana coupling matrix and simultaneously provides the insights about parity breaking scale.

Recent work has highlighted the importance of crossed products in correctly elucidating the operator algebraic approach to quantum field theories. In the gravitational context, the crossed product simultaneously promotes von Neumann algebras associated with subregions in diffeomorphism covariant quantum field theories from type III to type II, and provides the necessary ingredients to gravitationally dress operators, thereby enforcing the constraints of the theory. In this note we enhance the crossed product construction to the context of general gauge theories with arbitrary combinations of internal and spacetime local symmetries. This is done by leveraging the correspondence between the crossed product and the extended phase space. We then undertake a detailed study of constraint quantization from the perspective of a generic crossed product algebra. We study and compare four distinct approaches to constraint quantization from this point of view: refined algebraic quantization, BRST quantization, path integral quantization, and the commutation theorem for crossed products. Far from simply reproducing existing analyses, the operator algebraic viewpoint sheds new light on old problems by reformulating the dressing of operators in terms of conditional expectations and other closely related projection maps. We conclude by applying our approach to the constraint quantization of three distinct gauge theories including a discussion of gravity on null hypersurfaces.

A model of N 4-component massless fermions in a quartic self-interaction based on ref. [19] is investigated in the presence of chemical potential and temperature via optimized perturbation theory that accesses finite-N contributions. We use the generating functional approach to calculate the corrections to the effective potential of the model. The model introduces an auxiliary pseudo-vector field with a nontrivial minimum and is influenced by temperature (T) and chemical potential (μ). These thermodynamic quantities are introduced through Matsubara formalism. Thereby, the integrals are modified, and via the principle of minimum sensitivity, we obtain the gap equations of the model. The correspondent finite-N solutions of these equations define the vacuum states of the model associated with the background pseudo-vector field. In particular, one focuses on its temporal component that acts as an effective chiral chemical potential. We discuss the solutions of the four cases in which $(T=0,\mu =0)$, $(T\ne 0,\mu \ne 0)$, $(T\ne 0,\mu =0)$ and $(T=0,\mu \ne 0)$, where the effective potential is so obtained as a function of the background vector field, the chemical potential, and the temperature. The model shows the finite-N corrections generate first-order phase transitions on the self-interacting fermions for the case $N=1$ and the persistence of a second-order phase transition for $N\ge 2$.

We have investigated a weakly q-deformed algebra, which leads to non-Hermitian operators. It has been explicitly shown that the harmonic oscillator Hamiltonian is quasi-Hermitian, and that the corresponding physical Hilbert-space metric Θ differs from that obtained in Ref. [1], by hermitizing the position operator. The reality of the Hamiltonian eigenvalues has been illustrated by analytically computing the first order correction to the energy spectrum of the harmonic oscillator (HO). Furthermore, we have shown that this q-deformation leads to a GUP with minimal uncertainties in both position and momentum measurements. Moreover, the physical implications of this q-deformation, have been investigated by studying the thermostatistics of a system of HOs and an ideal gas. For both systems, we computed the partition function, and then we derived some thermodynamic functions. In addition, for the ideal gas, a modified equation of state and a generalized Mayer's equation, consistent with the real behavior of gases, have been established. The obtained results show that the impact of this model would be significant at high temperatures. However, unlike earlier research, we observe that this q-deformation induced the similar corrections regardless of the system under study.

The wormhole solution in dRGT massive gravity is examined in this paper in the background of non-commutative geometry. In order to derive the wormhole model, along with the zero tidal force, we assume that the matter distribution is given by the Gaussian and Lorentzian distributions. The shape function in both models involves the massive gravity parameters $m^2{c}_1$ and $m^2{c}_2$. But the spacetime loses its asymptotic flatness due to the action of the massive gravity parameter. It is noticed that the asymptotic flatness is affected by the repulsive effect induced in the massive gravitons that push the spacetime geometry very strongly. We observed that each model violates the null energy criteria, indicating the presence of exotic matter which is necessary to sustain the wormholes. The exotic matter is measured using the volume integral quantifier. Moreover, it is discovered that the model is stable under the hydrostatic equilibrium condition by utilizing the TOV equation. Finally, our research encompassed an exploration of the repulsive influence exerted by gravity. Our findings demonstrated that the presence of repulsive gravity results in a negative deflection angle for photons following null geodesics. Remarkably, we consistently observed negative values for the deflection angle across all values of $r_0$ in the two scenarios examined. This consistent negativity unequivocally signifies the manifestation of the repulsive gravity effect.