Constructing phantom cosmologies from standard scalar field universes

Area of Science:

• Cosmology
• Theoretical Physics
• General Relativity

Background:

• Scalar field cosmologies are fundamental to understanding the universe's evolution.
• Phantom cosmologies present unique challenges and opportunities in cosmological models.
• Form-invariance transformations offer a novel mathematical approach to explore cosmological transformations.

Purpose of the Study:

• To demonstrate the application of form-invariance transformations for constructing phantom cosmologies.
• To establish a mathematical link between standard and phantom cosmological models.
• To investigate the persistence of this duality under brane-world modifications.

Main Methods:

• Relating two flat Friedmann-Robertson-Walker cosmologies with different barotropic indices.
• Analyzing the specific case where barotropic indices are negative reciprocals (gamma; = -gamma).
• Interpreting matter content via self-interacting scalar fields.

Main Results:

• A transformation is identified that links standard and phantom cosmologies.
• This duality is illustrated using models with exponential potentials.
• The duality is shown to be robust, persisting even with brane-world corrections to the Friedmann equation.

Conclusions:

• Form-invariance transformations provide a powerful tool for generating phantom cosmologies.
• The established duality offers new perspectives on the relationship between standard and exotic cosmological models.
• The findings have implications for understanding dark energy and the universe's accelerated expansion.