32 citations · 182 across the 18 of their papers we have counts for
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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…
Inflation by spin and torsion in Poincare gauge theory of gravity
Siamak Akhshabi, Elham Qorani, Fazeleh Khajenabi
In Poincare gauge theory of gravity, in addition to mass-energy content, spin is also a source for gravitational interactions. Although the effects of spin are negligible at low en…
Braneworld setup and embedding in teleparallel gravity
A. Behboodi, S. Akhshabi, K. Nozari
We construct the setup of a five-dimensional braneworld scenario in teleparallel gravity. Both cases of Minkowski and Friedmann-Robertson-Walker branes embedded in Anti de Sitter b…
Braneworld Teleparallel Gravity
Kourosh Nozari, A. Behboodi, S. Akhshabi
We study the gravity in the context of a braneworld teleparallel scenario. The geometrical setup is assumed to be Randall-Sundrum II model where a single positive tension brane is…
Matter stability in modified teleparallel gravity
A. Behboodi, S. Akhshabi, K. Nozari
We study the matter stability in modified teleparallel gravity or theories. We show that there is no Dolgov-Kawasaki instability in these types of modified teleparallel grav…
Effects of the Generalized Uncertainty Principle on the Inflation Parameters
Kourosh Nozari, Siamak Akhshabi
We investigate the effects of the generalized uncertainty principle on the inflationary dynamics of the early universe in both standard and braneworld viewpoint. We choose the Rand…
Orbits of particles in noncommutative Schwarzschild spacetime
Kourosh Nozari, Siamak Akhshabi
By considering particles as smeared objects, we investigate the effects of space noncommutativity on the orbits of particles in Schwarzschild spacetime. The effects of space noncom…
On the Stability of Planetary Circular Orbits in Noncommutative Spaces
Kourosh Nozari, Siamak Akhshabi
We investigate the effects of space noncommutativity and the generalized uncertainty principle on the stability of circular orbits of particles in both a central force potential an…