Power-law bounces in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mi>f</mml:mi> <mml:mo stretchy="false">(</mml:mo> <mml:mi>R</mml:mi> <mml:mo stretchy="false">)</mml:mo> </mml:math> gravity: Analysis of the ekpyros
We investigate the dynamics of the Friedmann-Lema\^{\i}tre-Robertson-Walker spacetime within the framework of $f(R)$ gravity using a compact, model-independent dynamical systems approach. By assuming a power-law scale factor, we explore ekpyrotic and accelerating solutions to address the big bang singularity. Our analysis demonstrates that a cosmological bounce, characterized by a transition from contraction to expansion, possibly avoids the singularity without directly using the Raychaudhuri equation, unlike previous approaches using specific $f(R)\ensuremath{\simeq}{R}^{n}$ forms. We identify a key fixed point in the phase space corresponding to the bounce, supported by perturbation analysis and qualitative description of trajectories in the phase space. The results suggest that $f(R)$ gravity provides a robust framework for nonsingular cosmologies.
Authors
- Saurya Das (ORCID: https://orcid.org/0000-0003-1191-8469)
- S. Shajidul Haque (ORCID: https://orcid.org/0000-0001-6216-5351)
- Peter K. S. Dunsby (ORCID: https://orcid.org/0000-0002-6271-9585)
- Seturumane Tema (ORCID: https://orcid.org/0000-0002-5355-0917)
Institutions
- University of Lethbridge (CA)
- University of Cape Town (ZA)
- North-West University (ZA)
- National Institute for Theoretical Physics (ZA)
- South African Radio Astronomy Observatory (ZA)
- Astronomical Observatory (RS)
Publication Details
- Journal
- Physical review. D/Physical review. D.
- Published
- 2025-11-21
- DOI
- https://doi.org/10.1103/rrnm-z3qy
- Primary Topic
- Cosmology and Gravitation Theories
- Type
- article
- Field-Weighted Citation Impact
- 0.00