Modern Physics Letters A

We provide a brief summary of a method to calculate improvements to the Veneziano amplitude, creating sub-leading nonlinearities in the Regge trajectory of states. We formulate it as an extension of a computation by Makeenko and Olesen. We begin in a confining gauge theory coupled to matter, rewriting the meson scattering amplitude as a specific path integral over shapes and sizes of closed Wilson loops using the worldline formalism. We then prescribe how to further the computation at strong coupling by employing holography, which provides a prescription for the expectation value of these Wilson loops in strongly coupled regimes. The computation we desire then appears to subsume to a certain calculation in the effective field theory of a string worldsheet embedded in a certain broad class of allowed holographic backgrounds. A convenient interaction picture presents itself naturally in this context, allowing us to draw Feynman diagrams corresponding to the first few corrections due to weaker coupling regimes. The answer we find has qualitatively the same features as other endeavors with the same objective.

Using the parity deformed Heisenberg algebra (RDHA), we first establish associated coherent states (RDCSs) for a pseudo-harmonic oscillator (PHO) system that are defined as eigenstates of a deformed annihilation operator. Such states can be expressed as superposition of an even and odd Wigner cat states.${}^{35}$ The RDCSs minimize a corresponding uncertainty relation, and resolve an identity condition through a positive definite measure which is explicitly derived. We introduce a class of single-mode excited coherent states (PARDCS) of the PHO through “m” times application of deformed creation operators to RDCS. For the states thus constructed, we analyze their statistical properties such as squeezing and sub-Poissonian statistics as well as their uncertainty relations.

A proposal to study the effect of interaction in an agegraphic dark energy model in DGP brane-world cosmology is presented in this paper. After explaining the details, we proceed to apply the dynamical system approach to the model to analyze its stability. We first constrain model parameters with a variety of independent observational data such as cosmic microwave background anisotropies, baryon acoustic oscillation peaks and observational Hubble data. Then, we obtain the critical points related to different cosmological epochs. In particular, we conclude that in the presence of interaction, dark energy dominated era could be a stable point if model parameters n and $\beta$, obey a given constraint. Also, big rip singularity is avoidable in this model.

In this work, we investigate the masses of a few heavy–light mesons with variational method, taking into account the two-loop effects in the static Cornell potential. Specifically, we consider two wave functions, Gaussian and Coulomb. Our analysis suggests that phenomenologically such approach is more successful in the heavy flavored meson sector than the stationary state perturbation theory and other approximation methods.

The formal framework for quantum mechanics is an infinite number of dimensional space. Hereby, in any analytical calculation of the quantum system, the energy eigenvalues and corresponding wave functions can be represented easily in a finite-dimensional basis set. In this work, the approximate analytical solutions of the hyper-radial Schrödinger equation are obtained for the generalized Wood–Saxon potential by implementing the Pekeris approximation to surmount the centrifugal term. The energy eigenvalues and corresponding hyper-radial wave functions are derived for any angular momentum case by means of state-of-the-art Nikiforov–Uvarov and supersymmetric quantum mechanics methods. Hence, the same expressions are obtained for the energy eigenvalues, and the expression of hyper-radial wave functions transforming each other is shown owing to these methods. Furthermore, a finite number energy spectrum depending on the depths of the potential well $V_0$ and $W$, the radial $n_r$ and $l$ orbital quantum numbers and parameters $D$, $a$, $R_0$ are also identified in detail. Next, the bound state energies and corresponding normalized hyper-radial wave functions for the neutron system of the ${}^{56}$Fe nucleus are calculated in $D=2$ and $D=3$ as well as the energy spectrum expressions of other higher dimensions are revealed by using the energy spectrum of $D=2$ and $D=3$.

In this paper, we investigate the behavior of the energy eigenvalues of the Schrödinger equation by using the canonical quantization method. We obtain the Hamiltonian of the Schrödinger equation by the Lagrangian in terms of the new coordinates. Then we calculate the partition function by the eigenvalues and the thermodynamic properties of the system in the superstatistics formalism for the modified Dirac delta and the Gamma distributions. All results in the limiting cases satisfy that of the harmonic oscillator. Furthermore, the effects of the all parameters in the problem of energy eigenvalues and thermodynamic properties are calculated and shown graphically.

We show the existence of a new class of $\beta$-functions which can govern the running of strong coupling constants in gauge field theories.

We propose a new form of Lagrangian that shows branching for the associated Hamiltonian and has relevance to the quadratic type and mixed linear-quadratic Liénard-type nonlinear dynamical equations on adjusting the underlying parameters. Non-uniqueness of the Lagrangian is pointed out and a particular one when Fourier transform is demonstrated to depict a momentum-dependent quantum-like mass system when expanded binomially.

We consider a (7 + k)-dimensional Einstein–Gauss–Bonnet (EGB) model with the cosmological $\mathrm{\Lambda }$-term. A cosmological model with three factor spaces of dimensions 3, 3 and k, k$>$2 is considered. Exact stable solutions with three (non-coinciding) Hubble-like parameters in these models are obtained. Some examples of solutions (e.g. with zero variation of the effective gravitational constant G) are considered in selected dimensions (for k = 5, 6).