The review presents general methods for treating complicated problems that cannot be
solved exactly and whose solution encounters two major difficulties. First, there are no small …

The review presents the development of an approach of constructing approximate solutions
to complicated physics problems, starting from asymptotic series, through optimized …

Reduced exciton mass, polarizability, and dielectric constant of the surrounding medium are
essential properties for semiconducting materials, and they have been extracted recently …

Van der Waals interactions are ubiquitous and they play an important role for the stability of
materials. Current understanding of this type of coupling is based on linear response theory …

It is widely comprehended that temperature may cause phonon-exciton scattering,
enhancing the energy level's linewidth and leading to some spectrum shifts. However, in the …

We have developed an analytical expression for s-state exciton energies in monolayer
transition metal dichalcogenides (TMDCs) as E ns=− Ry*× P n/(n− 0.5+ 0.479 r 0*/κ) 2, n= 1 …

The energy spectrum of a hydrogen atom in a plasma has been of interest in physics until
now. This problem is also quite important for astrophysics when considering the system in a …

A two-dimensional helium atom (2D-helium) is a real subject for current studies, particularly
regarding a hot topic of negatively charged excitons (trions) in semiconducting monolayers …

We investigate the applicability of the two major approximations which are most commonly
employed in the study of the quantum Rabi model, namely the description of a resonant …

We investigate the large asymptotics of the-th eigenvalue for a class of unbounded self-
adjoint operators defined by infinite Jacobi matrices with discrete spectrum. In the case of …