مشخصات پژوهش

صفحه نخست /Wormholes in Poincare gauge ...
عنوان
Wormholes in Poincare gauge theory of gravity
عنوان مجله MODERN PHYSICS LETTERS A
نوع پژوهش مقاله چاپ شده
کلیدواژه‌ها
Wormhole,Modified Gravity Theories,Spacetime Torsion,Exact Solutions
چکیده
In this work, we study static spherically symmetric solutions representing wormhole con- figurations in Poincare gauge theory (PGT). The gravitational sector of the Lagrangian is chosen as a subclass of PGT Lagrangians for which the spin-0+ is the only propagating torsion mode. The spacetime torsion in PGT has a dynamical nature even in the absence of intrinsic angular momentum (spin) of matter, hence torsion can play a principal role in the case of usual spin-less gravitating systems. We therefore consider a spin-less mat- ter distribution with an anisotropic energy–momentum tensor (EMT) as the supporting source for wormhole structure to obtain a class of zero tidal force wormhole solutions. It is seen that the matter distribution obeys the physical reasonability conditions, i.e. the weak (WEC) and null (NEC) energy conditions either at the throat and throughout the spacetime. We further consider varying equations of state in radial and tangential directions via definitions wr (r) = pr (r)/ρ(r) and wt(r) = pt(r)/ρ(r) and investigate the behavior of state parameters at the throat of wormhole. We observe that our solutions allow for wormhole configurations without the need of exotic matter. Observational features of the wormhole solutions are also discussed utilizing gravitational lensing effects. It is found that the light deflection angle diverges at the throat (which indeed, effectively acts as a photon sphere) and can get zero and negative values depending on the model parameters.
پژوهشگران امیر هادیضیائی (نفر اول)، کریستینکوردا (نفر دوم)