32 citations · 182 across the 18 of their papers we have counts for
18 papers
The Role of Torsion in Trans-Planckian Physics
Elham Arabahmadi, Siamak Akhshabi
The torsion of spacetime, if exists, plays an important role at the very early universe when the spin density of particles was very high. It is generally believed that in extremely…
Gravitational Slip parameter and Gravitational Waves in Einstein-Cartan theory
Maryam Ranjbar, Siamak Akhshabi, Mohsen Shadmehri
We study the evolution of scalar and tensor cosmological perturbations in the framework of the Einstein-Cartan theory of gravity. The value of the gravitational slip parameter whic…
Cosmological Distances And Hubble Tension In Einstein-Cartan Theory
Siamak Akhshabi, Saboura Zamani
We analyze the measurement of cosmological distances in the presence of torsion in both Einstein-Cartan and Poincare gauge theory of gravity. Using the modified cosmological distan…
Gravitational lensing by a black hole in Poincar{é} gauge theory of gravity
Saboura Sadat Zamani, Siamak Akhshabi
Using a recently found black hole solution in the framework of the Poincar{é} gauge theory of gravity, we study gravitational lensing for a system where the lens is a static spheri…
Orbits of particles and black hole thermodynamics in a spacetime with torsion
S. Gharibi Nodijeh, S. Akhshabi, F. Khajenabi
We derive the static spherically symmetric vacuum solution for a spacetime with non-vanishing torsion by solving the field equations analytically. The effects of torsion appear as…
Light propagation and optical scalars in torsion theories of gravity
Siamak Akhshabi
We investigate the propagation of light rays and evolution of optical scalars in gauge theories of gravity where torsion is present. Recently the modified Raychaudhuri equation in…