Λ_s VCDM is a predictive model combining Λ_s CDM with VCDM gravity via an auxiliary scalar field and sigmoid-smoothed potentials to enable stable mirror AdS-to-dS transitions with possible transient acceleration.
Sudden Future Singularities
10 Pith papers cite this work. Polarity classification is still indexing.
abstract
We show that a singularity can occur at a finite future time in an expanding Friedmann universe even when the density is positive and the density plus the sum of the principal pressures is positive. Explicit examples are constructed and a simple condition is given which can be used to eliminate behaviour of this sort if it is judged to be unphysical.
citation-role summary
citation-polarity summary
roles
background 4polarities
background 4representative citing papers
Fractional gravity yields stable de Sitter expansion and exact bouncing solutions driven by phantom (w < -1) or ghost (negative energy) fluids, with results independent of the form-factor representation.
A unified dark energy model with sigmoid correction generates a spectrum of rip futures that all fit DESI, Pantheon+, and CMB data at the same level as ΛCDM.
Relativistic N-body simulations of Lambda_s CDM produce a redshift-dependent crest in the matter power spectrum ratio, peaking at 20-25% near the transition and leaving a 15-20% uplift at z=0 on group scales.
Introduces Fractional Holographic Dark Energy (FHDE) via fractionally corrected entropy from a modified Wheeler-DeWitt equation and studies its late-time cosmology, field reconstructions, and extensions to modified gravity theories.
Phantom Chaplygin gas forces the Einstein-frame lapse to change sign smoothly while the causal-frame lapse stays positive, yielding a robust non-singular bounce even with extra matter.
Dark energy models with pressure defined as a function of scale factor match ΛCDM observations today but develop finite-time future singularities, including exact scalar field representations and calculated effects on matter perturbation growth.
Effective phantom dark energy is a background-level reconstruction that does not imply fundamental pathologies such as ghost instabilities or null energy condition violation by the underlying stress tensor.
Classical solutions for F(R) gravity in Bianchi type I cosmology with barotropic matter are derived via the Hamiltonian formalism in two gauges.
Dark energy models with pressure as a function of scale factor produce type I-IV finite-time future singularities that exhibit similar late-time behavior.
citing papers explorer
-
$\Lambda_{\rm s}$CDM cosmology from a type-II minimally modified gravity
Λ_s VCDM is a predictive model combining Λ_s CDM with VCDM gravity via an auxiliary scalar field and sigmoid-smoothed potentials to enable stable mirror AdS-to-dS transitions with possible transient acceleration.
-
Cosmology of fractional gravity
Fractional gravity yields stable de Sitter expansion and exact bouncing solutions driven by phantom (w < -1) or ghost (negative energy) fluids, with results independent of the form-factor representation.
-
A Spectrum of Cosmological Rips and Their Observational Signatures
A unified dark energy model with sigmoid correction generates a spectrum of rip futures that all fit DESI, Pantheon+, and CMB data at the same level as ΛCDM.
-
Nonlinear Matter Power Spectrum from relativistic $N$-body Simulations: $\Lambda_{\rm s}$CDM versus $\Lambda$CDM
Relativistic N-body simulations of Lambda_s CDM produce a redshift-dependent crest in the matter power spectrum ratio, peaking at 20-25% near the transition and leaving a 15-20% uplift at z=0 on group scales.
-
An Interplay Between Fractional Calculus and Holographic Dark Energy
Introduces Fractional Holographic Dark Energy (FHDE) via fractionally corrected entropy from a modified Wheeler-DeWitt equation and studies its late-time cosmology, field reconstructions, and extensions to modified gravity theories.
-
Geodesic completion of big bangs from emergent geometry
Phantom Chaplygin gas forces the Einstein-frame lapse to change sign smoothly while the causal-frame lapse stays positive, yielding a robust non-singular bounce even with extra matter.
-
$\Lambda$CDM-like models with future singularities
Dark energy models with pressure defined as a function of scale factor match ΛCDM observations today but develop finite-time future singularities, including exact scalar field representations and calculated effects on matter perturbation growth.
-
Effective Phantom Dark Energy: What Cosmological Reconstruction Does and Does Not Imply
Effective phantom dark energy is a background-level reconstruction that does not imply fundamental pathologies such as ghost instabilities or null energy condition violation by the underlying stress tensor.
-
F(R,..) theories from the point of view of the Hamiltonian approach: non-vacuum Anisotropic Bianchi type I cosmological model
Classical solutions for F(R) gravity in Bianchi type I cosmology with barotropic matter are derived via the Hamiltonian formalism in two gauges.
-
Finite scale factor and future singularities
Dark energy models with pressure as a function of scale factor produce type I-IV finite-time future singularities that exhibit similar late-time behavior.