In this work, we observe that in the presence of string cloud parameter $a$ and quintessence $\gamma$, with equation state $\omega_q={-2}/{3}$ radius shadow Schwarzschild black hole increases as compared pure case. The existence both quintessential dark energy strings magnify size hence strength gravitational field around increases. Using data collected by Event Horizon Telescope (EHT) collaboration for M87* Sgr A*, obtain upper bounds on values parameters $\gamma$. Further, see effects...

Abstract In this study, the gravitational deflection angle of photons in weak field limit (or angle) and shadow cast by electrically charged spherically symmetric static Kiselev black hole (BH) string cloud background are investigated. The influences BH charge Q , quintessence parameter γ a on studied using Gauss-Bonnet theorem, addition to studying radius photon spheres size spacetime geometry charged-Kiselev clouds. Moreover, we study effects plasma (uniform non-uniform) surrounded clouds...

We investigate the null geodesics and shadow cast by Kerr-Newman-Kiselev-Letelier (KNKL) black hole for equation of state parameter $\omega_q=-2/3$ different values spacetime parameters, including quintessence $\gamma$, cloud string (CS) $b$, spin $a$ charge $Q$ hole. notice that increasing parameters $\gamma$ $b$ size KNKL increases consequently strength gravitational field increases. On other hand with increase in decreases. Further hole, we see distortion becomes more prominent. Moreover...

Abstract This study is devoted to explore the physical aspects of wormhole geometry under embedded class-1 spacetime in $$f(T,\tau )$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>f</mml:mi> <mml:mo>(</mml:mo> <mml:mi>T</mml:mi> <mml:mo>,</mml:mo> <mml:mi>τ</mml:mi> <mml:mo>)</mml:mo> </mml:mrow> </mml:math> gravity, where $$\tau $$ denotes trace energy-momentum tensor and T torsion. We derive solutions by considering spherically symmetric static spacetime....

Abstract This analysis is devoted to exploring the interesting aspects of wormhole geometry. The energy conditions are checked for two different new generic shape functions, which satisfy required properties. presence exotic matter confirmed due violation in background f ( R , T ) gravity as well general relativity case. traversable wormholes respecting null can be realized both considered frameworks. A thin-shell around a geometry with functions obtained by using cut and paste approach...

Abstract This study explores new wormhole solutions in the background of teleparallel gravity. All energy conditions are investigated for two different calculated shape functions. The presence exotic matter is confirmed due to violation conditions. Thin-shell around geometry obtained by using cut and paste approach taking Schwarzschild black hole as an exterior manifold. stability thin-shell explored linearized radial perturbation about equilibrium shell radius both choices It concluded that...

Abstract This study explores the wormhole solutions utilizing notion of conformal symmetry in background gravity. The exact shape functions are calculated using Gaussian and Lorentzian distributions as noncommutative source energy density. All conditions checked for two different functions. presence exotic matter is confirmed due to violation null conditions. physical aspects epicyclic frequencies test particles discussed spacetime geometry obtained wormholes current analysis it shown that...

Abstract The null and timelike geodesic motion in the vicinity of Schwarzschild black hole presence string cloud parameter a quintessence field q is studied. ranges for both parameters are determined, which allow existence hole. In radial photon, coordinate time t first decreases with increasing values then close proximity horizon hole, there turning point, after effect just opposite on . For massive particles, proper $$\tau $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML">...

Abstract We study the motion of test particles and photons in vicinity (2+1)-dimensional Gauss–Bonnet (GB) BTZ black hole. find that presence coupling constant serves as an attractive gravitational charge, shifting innermost stable circular orbits outward with respect to one for this theory four dimensions. Further, we consider lensing, GB gravity (2+1) dimensions show parameter causes bending angle first increase inverse closest approach distance, $$u_0$$ <mml:math...

Abstract This study explores the Rastall theory of modified gravity for three different compact stars based on observational facts, by assuming Karmarkar condition with an anisotropic fluid profile. We adopt explicit <?CDATA ${{\rm{g}}}_{{rr}}$?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi mathvariant="normal">g</mml:mi> </mml:mrow> mathvariant="italic">rr</mml:mi> </mml:msub> </mml:math> metric potential element, which fulfills...

The dynamics of a charged particle moving around slowly rotating Kerr black hole in the presence an external magnetic field is investigated. We are interested exploring conditions under which can escape from gravitational after colliding with another particle. velocity innermost stable circular orbit calculated. effective potential and angular momentum analyzed. This work serves as extension preceding paper dealing Schwarzschild (Zahrani et al., Phys Rev D 87:084043, 2013).

This paper investigates the Noether symmetry approach in modified [Formula: see text] theory of gravity, where is Ricci scalar, a scalar field and kinetic energy term. For this purpose, we consider Locally Rotationally Symmetric (LRS) Bianchi Type-I spacetimes. The cosmological solutions are developed through approach. determining equations computed context point-like Lagrangian for gravity. In particular, three different cases taken into account LRS Some important conserved quantities...

Abstract We study the particle dynamics around a black hole (BH) in f ( Q ) gravity. First, we investigate influence of parameters gravity on horizon structure BH, photon orbits and radius innermost stable circular orbit (ISCO) massive particles. further effects shadow cast by BH. Moreover, consider weak gravitational lensing using general method, where also explore deflection angle light rays BH uniform nonuniform plasma mediums.

Abstract In this work we focus on the effects of Starobinsky–Bel–Robinson (SBR) gravity parameter and external magnetic field motion charged test particles dipoles moving around a black hole in selected theory. We take to be uniform aligned along axis symmetry. Our results reveal that effect SBR is very strong close environment central while farther distances diminishes quickly. see particle always dominating over distances. show for interaction can mimic spin up rapid rotations prograde...

The current paper is devoted to investigating wormhole solutions with an exponential gravity model in the background of f ( R ) theory. Spherically symmetric static spacetime geometry chosen explore anisotropic fluid source. behavior traceless matter studied by employing a particular equation state describe important properties shape-function geometry. Furthermore, energy conditions and stability analysis are done for two specific shape-functions. It seen that condition be violated both...