Relaxing cosmological tensions with a sign switching cosmological constant: Improved results with Planck, BAO, and Pantheon data

Ö Akarsu, S Kumar, E Özülker, JA Vazquez, A Yadav - Physical Review D, 2023 - APS
We present a further observational analysis of the Λ s CDM model proposed in Akarsu et
al.[Phys. Rev. D 104, 123512 (2021) PRVDAQ 2470-0010 10.1103/PhysRevD …

Cosmological models in scale-independent energy-momentum squared gravity

Ö Akarsu, NM Uzun - Physics of the Dark Universe, 2023 - Elsevier
Scale-independent EMSG is a particular model of energy–momentum squared gravity
(EMSG) in which the new terms in the Einstein field equations arising from the EMSG theory …

Equivalence of matter-type modified gravity theories to general relativity with nonminimal matter interaction

Ö Akarsu, M Bouhmadi-López, N Katırcı, E Nazari… - Physical Review D, 2024 - APS
In this study, we first establish that gravity models incorporating matter-related terms, such as
f (L m), f (g μ ν T μ ν), and f (T μ ν T μ ν), into the usual matter Lagrangian density L m, are …

Compartmentalization and coexistence in the dark sector of the universe

A Paliathanasis, K Duffy, A Halder, A Abebe - Physics of the Dark Universe, 2025 - Elsevier
We revise the cosmological interaction between dark energy and dark matter. More
precisely, we focus on models that support compartmentalization or coexistence in the dark …

Relativistic binary systems in scale-independent energy–momentum squared gravity

Ö Akarsu, E Nazari, M Roshan - Monthly Notices of the Royal …, 2023 - academic.oup.com
In this paper, we study the gravitational-wave (GW) radiation and radiative behaviour of
relativistic compact binary systems in the scale-independent energy–momentum squared …

Dynamics of the -body system in energy-momentum squared gravity: Equations of motion to the first post-Newtonian order

E Nazari - Physical Review D, 2024 - APS
In the energy-momentum squared gravity (EMSG), the matter energy-momentum tensor is
not conserved due to nonminimal interaction between the usual and modified matter fields …

4D Einstein–Gauss–Bonnet cosmology with Chameleon mechanism

A Paliathanasis - General Relativity and Gravitation, 2024 - Springer
We explore the impact of the chameleon mechanism in scalar field Einstein–Gauss–Bonnet
gravity on the dynamics of cosmological parameters. Conducting a thorough analysis of the …

Weak field and slow motion limits in energy–momentum powered gravity

Ö Akarsu, AK Çamlıbel, N Katırcı, I Semiz… - Physics of the Dark …, 2023 - Elsevier
We explore the weak field and slow motion limits, Newtonian and Post-Newtonian limits, of
the energy–momentum powered gravity (EMPG), viz., the energy–momentum squared …

Cosmological perturbations in the energy-momentum squared gravity theory: constraints from gravitational wave standard sirens and redshift space distortions

QM Fu, X Zhang - arXiv preprint arXiv:2408.01665, 2024 - arxiv.org
We investigate the linear cosmological perturbations in the context of the so-called energy-
momentum squared gravity (EMSG) theory. Recent researches show that the EMSG theory …

Compartmental and Coexistence in the Dark Sector of the Universe

A Paliathanasis, K Duffy, A Halder, A Abebe - arXiv preprint arXiv …, 2024 - arxiv.org
We revise the cosmological interaction between dark energy and dark matter. More
precisely, we focus on models that support compartmentalization or co-existence in the dark …