Lorentzian quantum cosmology with torsion
arXiv:2305.01690 · doi:10.1103/PhysRevD.109.043525
Abstract
We evaluate the Lorentzian gravitational path integral in the presence of non-vanishing torsion with the application of the Picard-Lefschetz theory for minisuperspaces corresponding to a number of phenomenological bouncing cosmological models as well as for the inflationary paradigm. It turns out that the semi-classical wave function derived from the saddle points of the path integral formalism coincides with the solutions of the Wheeler-DeWitt equation. Intriguingly, our analysis showed that the relative probability, derived using these semi-classical wave functions favors universes with smaller values of torsion. Moreover, we find that in the inflationary case, non-zero values of a certain parity-violating component of the torsion enhance the power in the large physical length scales, which can have important observational implications. On the other hand, in the case of bouncing models, the power spectrum is characterized by an initial region of growth, an intermediate oscillatory region, and then again a final region of growth. The shape of the power spectrum in the initial and intermediate regions is sensitive to the abundance of the bounce-enabling matter and torsion, along with the initial wave function of the universe, while the final size modifies the behavior of the power spectrum in the smaller length scales.
v2 is published in Physical Review D with minor changes
References in corpus (56)
- Physical Aspects of the Space-Time Torsion
- Bouncing Cosmologies: Progress and Problems
- Lorentzian Quantum Cosmology
- Cosmology with torsion: An alternative to cosmic inflation
- The Classical Universes of the No-Boundary Quantum State
- The No-Boundary Measure of the Universe
- No smooth beginning for spacetime
- Cosmological Inflation and the Quantum Measurement Problem
- Torsion Cosmology and the Accelerating Universe
- No Rescue for the No Boundary Proposal
- Does a Randall-Sundrum scenario create the illusion of a torsion-free universe?
- Tunneling wave function of the universe
- Review of the No-Boundary Wave Function
- Probabilities in Quantum Cosmological Models: A Decoherent Histories Analysis Using a Complex Potential
- The No-Boundary Proposal as a Path Integral with Robin Boundary Conditions
- What is the No-Boundary Wave Function of the Universe?
- No-boundary prescriptions in Lorentzian quantum cosmology
- Primordial scalar power spectrum from the Euclidean Big Bounce
- Black hole entropy in 3D gravity with torsion
- Tunneling wave function of the universe II: the backreaction problem
- Primordial scalar power spectrum from the hybrid approach in loop cosmologies
- Allowable complex metrics in minisuperspace quantum cosmology
- The Vacuum State of Primordial Fluctuations in Hybrid Loop Quantum Cosmology
- Spacetime thermodynamics in the presence of torsion
- Susskind's Challenge to the Hartle-Hawking No-Boundary Proposal and Possible Resolutions
- Primordial power spectrum from the dressed metric approach in loop cosmologies
- Uses of Complex Metrics in Cosmology
- Quantum Incompleteness of Inflation
- Einstein-Cartan Gravity with Torsion Field Serving as Origin for Cosmological Constant or Dark Energy Density
- Classical Inflationary and Ekpyrotic Universes in the No-Boundary Wavefunction
- Power spectrum for perturbations in an inflationary model for a closed universe
- The no-boundary proposal in biaxial Bianchi IX minisuperspace
- Lessons for quantum cosmology from anti-de Sitter black holes
- Viable tensor-to-scalar ratio in a symmetric matter bounce
- Equivalence of the Chern-Simons state and the Hartle-Hawking and Vilenkin wave-functions
- Why has spacetime torsion such negligible effect on our universe?
- Noether Current, Black Hole Entropy and Spacetime Torsion
- On Gauss-bonnet gravity and boundary conditions in Lorentzian path-integral quantization
- The Wave Function of the Universe and CMB Fluctuations
- No-boundary Wave Function, Wheeler-DeWitt Equation and Path Integral Analysis of the Bouncing `Quantum' Cosmology
- Viable scalar spectral tilt and tensor-to-scalar ratio in near-matter bounces
- Surprises in Lorentzian path-integral of Gauss-Bonnet gravity
- A contextual Planck parameter and the classical limit in quantum cosmology
- The real Chern-Simons wave function
- Minisuperspace Quantum Cosmology from the Einstein-Cartan Path Integral
- A generalized Hartle-Hawking wavefunction
- Weiss variation for general boundaries
- Late-time acceleration driven by shift-symmetric Galileon in the presence of Torsion
- Eddington gravity with matter: An emergent perspective
- Quantum torsion and a Hartle-Hawking "beam''
- Does space-time torsion determine the minimum mass of gravitating particles?
- Quantum cosmology of pure connection general relativity
- Covariant spin-parity decomposition of the Torsion and Path Integrals
- Truly Lorentzian quantum cosmology
- Torsion and the Probability of Inflation
- Suppression of long-wavelength CMB spectrum from the no-boundary initial condition