# Resolving cosmological singularities

@article{Chamseddine2016ResolvingCS, title={Resolving cosmological singularities}, author={Ali H. Chamseddine and Viatcheslav F. Mukhanov}, journal={Journal of Cosmology and Astroparticle Physics}, year={2016}, volume={2017}, pages={009 - 009} }

We find a simple modification of the longitudinal mode in General Relativity which incorporates the idea of limiting curvature. In this case the singularities in contracting Friedmann and Kasner universes are avoided, and instead, the universe has a regular bounce which takes place during the time inversely proportional to the square root of the limiting curvature. Away from the bounce, corrections to General Relativity are negligible. In addition the non-singluar modification of General…

## 105 Citations

Limiting extrinsic curvature theory and stable non-singular anisotropic universe

- Physics
- 2020

We propose a class of theories that can limit scalars constructed from the extrinsic curvature. Applied to cosmology, this framework allows us to control not only the Hubble parameter but also…

Limiting curvature mimetic gravity and its relation to Loop Quantum Cosmology

- PhysicsGeneral Relativity and Gravitation
- 2019

Considering as usual that the underlying geometry of our universe is well described by the spatially flat Friedmann–Lemaître–Robertson–Walker line element, we review how the background of holonomy…

Canonical structure of general relativity with a limiting curvature and its relation to loop quantum gravity

- Physics
- 2018

Chamseddine and Mukhanov recently proposed a modified version of general relativity that implements the idea of a limiting curvature. In the spatially flat, homogeneous, and isotropic sector, their…

Cosmology at the top of the α′ tower

- PhysicsJournal of High Energy Physics
- 2021

Abstract
The cosmology of the fully α′-corrected duality-invariant action for the Neveu-Schwarz sector of string theory is revisited, with special emphasis on its coupling to matter sources. The…

Maximal extensions and singularities in inflationary spacetimes

- MathematicsClassical and Quantum Gravity
- 2018

Extendibility of inflationary spacetimes with flat spatial geometry is investigated. We find that the past boundary of an inflationary spacetime becomes a so-called parallely propagated curvature…

Reconstruction of Mimetic Gravity in a Non-Singular Bouncing Universe from Quantum Gravity

- PhysicsUniverse
- 2019

We illustrate a general reconstruction procedure for mimetic gravity. Focusing on a bouncing cosmological background, we derive general properties that must be satisfied by the function f(□ϕ)…

Asymptotically free mimetic gravity

- PhysicsThe European Physical Journal C
- 2019

The idea of “asymptotically free” gravity is implemented using a constrained mimetic scalar field. The effective gravitational constant is assumed to vanish at some limiting curvature. As a result…

Cosmological perturbations and stability of nonsingular cosmologies with limiting curvature

- Physics, Mathematics
- 2017

We revisit nonsingular cosmologies in which the limiting curvature hypothesis is realized. We study the cosmological perturbations of the theory and determine the general criteria for stability. For…

Non‐Flat Universes and Black Holes in Asymptotically Free Mimetic Gravity

- MathematicsFortschritte der Physik
- 2019

The recently proposed theory of “Asymptotically Free Mimetic Gravity” is extended to the general non‐homogeneous, spatially non‐flat case. We present a modified theory of gravity which is free of…

Theories with limited extrinsic curvature and a nonsingular anisotropic universe

- Physics
- 2020

We propose a class of theories that can limit scalars constructed from the extrinsic curvature. Applied to cosmology, this framework allows us to control not only the Hubble parameter but also…

## References

SHOWING 1-10 OF 17 REFERENCES

A nonsingular universe.

- Physics, MathematicsPhysical review letters
- 1992

This work proposes a modification of the Einstein theory of gravitation for which all isotropic cosmological solutions (even including matter) are nonsingular, and all solutions asymptotically approach de Sitter space, a solution with limiting curvature.

Cosmology with Mimetic Matter

- Physics
- 2014

We consider minimal extensions of the recently proposed Mimetic Dark Matter and show that by introducing a potential for the mimetic non-dynamical scalar field we can mimic nearly any gravitational…

Mimetic dark matter

- Physics
- 2013

A bstractWe modify Einstein’s theory of gravity, isolating the conformal degree of freedom in a covariant way. This is done by introducing a physical metric defined in terms of an auxiliary metric…

The singularities of gravitational collapse and cosmology

- MathematicsProceedings of the Royal Society of London. A. Mathematical and Physical Sciences
- 1970

A new theorem on space-time singularities is presented which largely incorporates and generalizes the previously known results. The theorem implies that space-time singularities are to be expected if…

Scale invariance in the spectral action

- Physics, Mathematics
- 2005

All desirable features with correct signs for the relevant terms are obtained uniquely and without any fine tuning in the spectral action of the noncommutative space defined by the standard model.

The Uncanny Precision of the Spectral Action

- Mathematics, Physics
- 2008

Noncommutative geometry has been slowly emerging as a new paradigm of geometry which starts from quantum mechanics. One of its key features is that the new geometry is spectral in agreement with the…

Cosmological Event Horizons, Thermodynamics, and Particle Creation

- Physics
- 1977

It is shown that the close connection between event horizons and thermodynamics which has been found in the case of black holes can be extended to cosmological models with a repulsive cosmological…

Limiting density of matter as a universal law of nature

- Physics
- 1982

It is suggested that the density of matter in nature is always less than or equal to a certain value rho/sub q/, which is constructed from universal constants: rho/sub q/ = c/sup 5//kappa/sup…

Classical theory of fields

- Physics, Geology
- 1952

The principle of relativity Relativistic mechanics Electromagnetic fields Electromagnetic waves The propagation of light The field of moving charges Radiation of electromagnetic waves Particle in a…

The Classical Theory of Fields fourth edition

- Butterworth, Heinemann
- 1980