8 papers
Curvature-induced phantom mimicry and cosmological bounces without violating the Dominant Energy Condition
Miguel Cruz, Samuel Lepe
We explore the active geometric contribution of spatial curvature in a closed universe, distinguishing between kinematic superacceleration and the strict violation of matter energy…
Torsional pseudo-inflation beyond Einstein-Cartan
Fernando Izaurieta, Samuel Lepe, Cristian Quinzacara
Torsion entered early-universe cosmology twice: through the nonsingular Einstein--Cartan bounce, where the quantum spin of fermions halts the contraction, and through the proposal…
No late-time role for adiabatic torsion: a no-go result for Hubble-cutoff holographic dark energy in Einstein--Cartan cosmology
Fernando Izaurieta, Samuel Lepe, Cristian Quinzacara
In Friedmann cosmology with Einstein--Cartan torsion, the homogeneous torsion mode compatible with a separately conserved matter sector scales as and enters the F…
Spatial curvature in Unimodular Gravity
Gilberto Aguilar-Pérez, Miguel Cruz, Samuel Lepe
We investigate the cosmological implications of unimodular gravity (UG) featuring energy diffusion and spatial curvature. While standard diffusion models often suffer from thermody…
Thermodynamic behavior of cosmological models with fractional entropy
Miguel Cruz, Diego da Silva, Simón González +3
We investigate the thermodynamic and phenomenological implications of a cosmological model governed by fractional entropy applied to the apparent horizon of a flat Friedmann-Lemaît…
Thermodynamic constraints and future singularities in Unimodular Gravity driven by phantom and non-phantom fluids
Norman Cruz, Samuel Lepe, Guillermo Palma +1
This work investigates future cosmological singularities in a flat FLRW universe filled with a single barotropic fluid, (), within the framework of unimodular gravity.…
Beyond Comoving Volume: Horizon Flux and Matter Creation in Modified Cosmology from the Unified First Law of Thermodynamics
Víctor H. Cárdenas, Miguel Cruz, Samuel Lepe
We explore the derivation of the Friedmann equations from a thermodynamic perspective, applying the unified first law of thermodynamics to the apparent horizon of a flat Friedmann-…
Gravitational Faraday Effect induced by Dark Matter Spin
F. Barriga, F. Izaurieta, S. Lepe +4
We show that the spin of dark matter induces a gravitational analog of the electromagnetic Faraday effect, where the polarization of gravitational waves undergoes a rotation as the…