In this work we demonstrate the experimental development of a system of frequency- locking of a diode laser on the wings of an atomic line. As an error signal, we use the transmission through a cell with parallel windows ...

The study of the physical properties of galaxies is very important to understand the behavior of the Universe. On the other hand, one of the great challenges of the General Theory of Relativity is to nd exact solutions ...

The concept of Dark Matter arises to explain an anomaly in the rotation curve of spiral galaxies, since then, researchers around the world have been trying to detect the particle that composes this matter. Without success ...

Topological defects are solutions of differential equations that connect distinct confi gurations of a system. For one-dimensional models these solutions are called kinks. In this work we will study the twist-like solutions, ...

The most common accepted cosmological theories are base don the assumption that the fundamental constants of nature, suchas the gravitational constant G, the new structure constant α, and others, are infact constant. Thus, ...