Results 81 to 90 of about 7,610 (173)

Any spacetime has a Bianchi type I spacetime as a limit

, 2010
Pick an arbitrary timelike geodesic in an arbitrary spacetime. We demonstrate that there is a particular limiting process, an "ultra-local limit", in which the immediate neighborhood of the timelike geodesic can be "blown up" to yield a general ...
Cropp, Bethan, Visser, Matt
core   +1 more source

Navigating Dementia: Political Materialities of Public Transport in the All‐Ageing Metropolis

Sociology of Health &Illness, Volume 47, Issue 3, March 2025.
ABSTRACT Age‐ and dementia‐friendliness are major areas of contemporary urban policy and scholarship, seeking to maintain older people and those with cognitive impairment in their own homes and communities. Such work relies on architectural augmentation to maximise the functionality of ageing bodies and minds and has been criticised for conceptualising
James Rupert Fletcher
wiley   +1 more source

Observational constraints on the Kerr and its several single-parameter modified spacetimes using quasi-periodic oscillation data

European Physical Journal C: Particles and Fields
This paper investigates the dynamical effects of particles moving in the Kerr spacetime and its nine single-parameter modified spacetimes, including Bardeen, Ayon-Beato and Garcia (ABG), Hayward, Kerr–Newman (KN), Kerr–Taub–NUT (KTN), Braneworld Kerr (BK)
Shining Yang, Jianbo Lu, Wenmei Li, Mou Xu, Jingyang Xu   +4 more
doaj   +1 more source

Kinematic Self-Similar Solutions of Locally Rotationally Symmetric Spacetimes

, 2010
This paper contains locally rotationally symmetric kinematic self-similar perfect fluid and dust solutions. We consider three families of metrics which admit kinematic self-similar vectors of the first, second, zeroth and infinite kinds, not only for the
Amir, M. Jamil, Sharif, M.
core   +1 more source

Signatures of non-metricity on dynamical analysis of isotropic cosmological models

Nuclear Physics B
The characteristics of compact stars are examined in this study utilizing the Kohler-Chao-Tikekar and Tolman IV spacetime models. This study is framed within the f(Q) gravity, a geometric theory of gravity where spacetime curvature is describe by the non-
Tayyab Naseer, M. Sharif, M. Waqas, Kottakkaran Sooppy Nisar, Mohammed Zakarya   +4 more
doaj   +1 more source

Characterisation of orthogonal perfect fluid cosmological spacetimes

, 1994
We consider the general orthogonal metric separable in space and time variables in comoving coordinates. We then characterise perfect fluid models admitted by such a metric. It turns out that the homogeneous models can only be either FLRW or Bianchi I while the inhomogeneous ones can only admit $G_2 $ (two mutually as well as hypersurface orthogonal ...
Dadhich, Naresh, Patel, L. K., Govinder, K. S., Leach, P. G. L.   +3 more
openaire   +2 more sources

Dynamical stability of fluid spheres in spacetimes with a nonzero cosmological constant

, 2007
The Sturm-Liouville eigenvalue equation for eigenmodes of the radial oscillations is determined for spherically symmetric perfect fluid configurations in spacetimes with a nonzero cosmological constant and applied in the cases of configurations with ...
Hledik, Stanislav, Mrazova, Kristina, Stuchlik, Zdenek   +2 more
core   +1 more source

Influences of perfect fluid dark matter on coinciding validity of the weak gravity and weak cosmic censorship conjectures for Kerr-Newman black hole

Nuclear Physics B
One of the main difficulties in general relativity is the potential conflict between the weak gravity conjecture (WGC) and weak cosmic censorship conjecture (WCCC).
Jafar Sadeghi, Saeed Noori Gashti
doaj   +1 more source

Reissner-Nordström black holes surrounded by perfect fluid dark matter: Testing the viability of weak gravity conjecture and weak cosmic censorship conjecture simultaneously

Physics Letters B
A possible violation of the weak gravity conjecture (WGC) by cosmic censorship is one of the major challenges in the field of general relativity. The cosmic censorship is a fundamental principle that ensures the consistency of the theory of gravity ...
Jafar Sadeghi, Saeed Noori Gashti
doaj   +1 more source

Weakly B-Symmetric Warped Product Manifolds with Applications

Axioms
This work presents a comprehensive study of weakly B-symmetric warped product manifolds (WBS)n, a natural extension of several classical curvature-restricted geometries including B-flat, B-parallel, and B-recurrent manifolds.
Bang-Yen Chen, Sameh Shenawy, Uday Chand De, Safaa Ahmed, Hanan Alohali   +4 more
doaj   +1 more source