At the beginning of the twentieth century, the quantum nature of thermal electromagnetic radiation was a subject of intense interest. This was sparked by Max Planck’s discovery that the spectral distribution of light emerging from a thermal body could be explained only if the radiators emitting the energy occurred in discrete energy states. This induced Albert Einstein to conclude in 1905 that ...

We present a procedure to compute the absolute free energy of solid phases by Monte Carlo simulation. The method is based on the so-called "Einstein-crystal" method of Frenkel and Ladd [J. Chem. Phys. 81, 3188 (1984)]. The new technique is more general and simplifies the calculation for systems with hard core interactions. In addition, the reference Einstein crystal is built up to fulfill trans...

In this paper we study curvature properties of semi - symmetric type of totally umbilical radical transversal lightlike hypersurfaces $(M,g)$ and $(M,widetilde g)$ of a K"ahler-Norden manifold $(overline M,overline J,overline g,overline { widetilde g})$ of constant totally real sectional curvatures $overline nu$ and $overline {widetilde nu}$ ($g$ and $widetilde g$ are the induced metrics on $M$...

a gyrogroup is a nonassociative group-like structure modelled on the space of relativistically admissible velocities with a binary operation given by einstein's velocity addition law. in this article, we present a few of groups sitting inside a gyrogroup $g$, including the commutator subgyrogroup, the left nucleus, and the radical of $g$. the normal closure of the commutator subgyrogroup, ...

Intuitionistic fuzzy information aggregation plays an important part in Atanassov’s intuitionistic fuzzy set theory, which has emerged to be a new research direction receiving more and more attention in recent years. In this paper, we first introduce some operations on intuitionistic fuzzy sets, such as Einstein sum, Einstein product, Einstein exponentiation, etc., and further develop some new ...

The notion of coupled Kähler–Einstein metrics was introduced recently by Hultgren–Witt Nyström. In this paper we discuss deformation a metric on Fano manifold. We obtain necessary and sufficient condition for to be deformed another manifold admitting non-trivial holomorphic vector fields. addition also Käher–Einstein when the complex structure varies.

The d-dimensional string generated gravity models lead to Einstein-Maxwell equations with quadratic order correction term called the Gauss-Bonnet term. We calculate the quasinormal modes for the d-dimensional charged black hole in the framework of this model. The quasinormal spectrum essentially depends upon the Gauss-Bonnet coupling parameter α which is related to the string scale, and is tota...