# Nonsingular, big-bounce cosmology from spinor-torsion coupling

@article{Popawski2012NonsingularBC, title={Nonsingular, big-bounce cosmology from spinor-torsion coupling}, author={Nikodem J. Popławski}, journal={Physical Review D}, year={2012}, volume={85}, pages={107502} }

The Einstein-Cartan-Sciama-Kibble theory of gravity removes the constraint of general relativity that the affine connection be symmetric by regarding its antisymmetric part, the torsion tensor, as a dynamical variable. The minimal coupling between the torsion tensor and Dirac spinors generates a spin-spin interaction which is significant in fermionic matter at extremely high densities. We show that such an interaction averts the unphysical big-bang singularity, replacing it with a cusp-like… Expand

#### 124 Citations

Fermi-Bounce Cosmology and Scale-Invariant Power Spectrum

- Physics
- 2014

We develop a non-singular bouncing cosmology using a non-trivial coupling of general relativity to fermionic fields. The usual Big Bang singularity is avoided thanks to a negative energy density… Expand

Analysis of big bounce in Einstein–Cartan cosmology

- Physics
- 2019

We analyze the dynamics of a homogeneous and isotropic universe in the Einstein--Cartan theory of gravity. The spin of fermions produces spacetime torsion that prevents gravitational singularities… Expand

Big Bounce and Closed Universe from Spin and Torsion

- Physics
- The Astrophysical Journal
- 2019

We analyze the dynamics of a homogeneous and isotropic universe in the Einstein$--$Cartan theory of gravity. The coupling between the spin and torsion prevents gravitational singularities and… Expand

ELKO SPINOR MODEL WITH TORSION AND COSMOLOGY

- Physics
- 2013

We investigate the cosmology of ELKO spinor model when minimal coupling with torsion is included. Unlike the Dirac spinor which interacts only with the totally anti-symmetric components of torsion… Expand

Cosmological singularities and bounce in Cartan-Einstein theory

- Physics
- 2017

We consider a generalized Einstein-Cartan theory, in which we add the unique covariant dimension four operators to general relativity that couples fermionic spin current to the torsion tensor (with… Expand

Non-minimally coupled scalar field cosmology with torsion

- Physics
- 2018

In this work we present a generalized Brans-Dicke lagrangian including a non-minimally coupled Gauss-Bonnet term without imposing the vanishing torsion condition. In the resulting field equations,… Expand

Non-Parametric Reconstruction of an Inflaton Potential from Einstein–Cartan–Sciama–Kibble Gravity with Particle Production

- Physics
- 2016

Abstract The coupling between spin and torsion in the Einstein–Cartan–Sciama–Kibble theory of gravity generates gravitational repulsion at very high densities, which prevents a singularity in a black… Expand

Spinor driven cosmic bounces and their cosmological perturbations

- Physics
- 2017

When coupling fermions to gravity, torsion is naturally induced. We consider the possibility that fermion bilinears can act as a source for torsion, altering the dynamics of the early universe such… Expand

Einstein–Cartan–Dirac gravity with U(1) symmetry breaking

- Physics
- 2019

Einstein-Cartan theory is an extension of the standard formulation of General Relativity where torsion (the antisymmetric part of the affine connection) is non-vanishing. Just as the space-time… Expand

Mimetic Einstein-Cartan-Sciama-Kibble (ECSK) gravity

- Physics
- 2020

In this paper, we formulate the Mimetic theory of gravity in first-order formalism for differential forms, i.e., the mimetic version of Einstein-Cartan-Sciama-Kibble (ECSK) gravity. We consider… Expand

#### References

SHOWING 1-10 OF 48 REFERENCES

Attractive spin-spin contact interactions in the Einstein-Cartan-Sciama-Kibble torsion theory of gravitation

- Physics
- 1977

Kerlick has obtained the unexpected result that the spin-spin contact interactions, which are characteristic of the Einstein-Carton-Sciama-Kibble theory of gravitation, are attractive for the case of… Expand

Friedmann-like cosmological models without singularity

- Physics
- 1978

The Einstein-Cartan theory of gravitation (“general relativity with spin”) provides a specific spin-spin contact interaction of matter, in addition to the usual long-range gravity. This new… Expand

Some cosmological models with spin and torsion

- Physics
- 1976

In axially-symmetric cosmological models of the Einstein-Cartan theory (which may be briefly called ‘general relativity plus spin’), the axis of symmetry is at the same time the direction of the… Expand

Big bounce from spin and torsion

- Physics
- 2012

The Einstein-Cartan-Sciama-Kibble theory of gravity naturally extends general relativity to account for the intrinsic spin of matter. Spacetime torsion, generated by spin of Dirac fields, induces… Expand

Some cosmological models with spin and torsion, I

- Physics
- 1976

The Einstein-Cartan theory, which is a slight modification of the general theory of relativity, is almost indistinguishable in its practical consequences from the latter theory. A characteristic… Expand

Nonsingular Dirac particles in spacetime with torsion

- Physics
- 2010

Abstract We use the Papapetrou method of multipole expansion to show that a Dirac field in the Einstein–Cartan–Kibble–Sciama (ECKS) theory of gravity cannot form singular configurations concentrated… Expand

''Bouncing'' of simple cosmological models with torsion

- Physics
- 1976

Abstract The known cosmological solutions of the Einstein-Cartan-Sciama-Kibble (ECSK) field equations are reviewed. The prevention of singularities is explained by means of the extension of the… Expand

Cosmology and Particle Pair Production via Gravitational Spin Spin Interaction in the Einstein-Cartan-Sciama-Kibble Theory of Gravity

- Physics
- 1975

General relativity with spin and torsion [the Einstein-Cartan-Sciama-Kibble (ECSK) theory] provides a more complete account of local gauge invariance with respect to the Poincar\'e group than is… Expand

Cosmology with torsion: An alternative to cosmic inflation

- Physics
- 2010

Abstract We propose a simple scenario which explains why our Universe appears spatially flat, homogeneous and isotropic. We use the Einstein–Cartan–Kibble–Sciama (ECKS) theory of gravity which… Expand

Spin and torsion may avert gravitational singularities

- Physics
- 1973

IT has long been recognized that isotropic models of the world are singular. The models, be they Newtonian or based on Einstein's equations of general relativity, lead to the prediction of at least… Expand