Extended tachyon field using form invariance symmetry

IVÁN E. SÁNCHEZ G.

PHYSICAL REVIEW D

AMER PHYSICAL SOC

Lugar: New York; Año: 2014 vol. D

1550-7998

In this work we illustrate how form-invariance transformations (FITs) can be used to construct phantom and complementary tachyon cosmologies from standard tachyon field universes. First we show how these transformations act on the Hubble expansion rate, and the energy density, and pressure of the tachyon field. Then we use the FIT to generate three different families of the tachyon field. In other words, the FIT generate new cosmologies from a known ``seed´´ one, in particular we apply the FIT to the ordinary tachyon field to obtain two types of tachyon species, denoted as the phantom and complementary tachyons. We see that the FIT allows us to pass from a nonstable cosmology to a stable one and vice versa. Finally, as an example, we apply the transformations to an inverse-square potential, $V propto phi^{-2}$, and generate the extended tachyon field.