Abstract Employing the covariant language of two-spinors, we find what conditions a curved four-dimensional Lorentzian spacetime must satisfy for existence second order symmetry operator massive Dirac equation. The are formulated as set Killing spinors satisfying linear differential equations. Using these spinors, then state most general form such an operator. Partial results zeroth and first p...

Various aspects of infrared radiative transfer through clouds are investigated. First, three solutions to the IR radiative transfer equation are presented and assessed, each corresponding to a different approximation for the Planck function. It is shown that the differences in results between solutions with linear and exponential dependence of the Planck source function are small for typical ve...

Molecule optimization is an important problem in chemical discovery and has been approached using many techniques, including generative modeling, reinforcement learning, genetic algorithms, much more. Recent work also...

Fullerene is a cage-like carbon allotrope admitting vast range of applications. Some the important fullerenes are C54,C58,C60,C70,C74,C76,C78,C80C82,C84,C86,C90. The physical properties can be exhibited using degree-based topological indices. sum based geometric arithmetic index significant in this manner. atomic bond connectivity, Randic, first and second Zagreb indices well known We have dete...

The Equivalence Principle is a key element in the development of General Relativity. In one its formulations, states that reference frame at rest uniform gravitational field equivalent to uniformly accelerated motion absence any gravitation field. We analyze spacetime surrounding non-rotating spherically symmetric charged body, known as Reissner–Nordström geometry, and exhibit coordinate transf...

All the drugs used as analgesic agent have some systemic side effects. For the researchers, the prospects of overcoming the side effects of a drug, achieving an effect at a much lower dose is very attractive. Modification of the structure of a known drug is one way to develop new drugs. For this purpose, we have optimized the pyrimidobenzimidazole derivatives using molecular modeling studies. Q...