227 citations · 340 across the 11 of their papers we have counts for
11 papers
Disformal interactions in the Dark Sector: From driving Early Dark Energy to confronting cosmological tensions
Pulkit Bansal, Joseph P. Johnson, S. Shankaranarayanan
The CDM model faces significant challenges, including an incomplete understanding of the dark sector and persistent tensions in the Hubble constant and the clustering amplitude.…
Kernel dependence of the Gaussian Process reconstruction of late Universe expansion history
Joseph P Johnson, H. K. Jassal
In this work, we discuss model-independent reconstruction of the expansion history of the late Universe. We use Gaussian Process Regression (GPR) to reconstruct the evolution of va…
Interacting dark sector from Horndeski theories and beyond: Mapping fields and fluids
Pulkit Bansal, Joseph P Johnson, S. Shankaranarayanan
In Cosmology, when dissipative effects are minimal, the energy content of the Universe can be effectively described as a sum of perfect fluids. Perfect fluid descriptions ensure th…
A test of Einstein's equivalence principle in future VLBI observations
Joseph P Johnson, Susmita Jana, S. Shankaranarayanan
We show that very-long-baseline-interferometry (VLBI) observations of supermassive black holes will allow us to test the fundamental principles of General Relativity (GR). GR is ba…
Modified theories of Gravity: Why, How and What?
S. Shankaranarayanan, Joseph P Johnson
General Relativity (GR) was proven via the direct detection of gravitational waves from the mergers of the binary black holes and binary neutron stars by the Advanced LIGO and Adva…
Can we bypass no-go theorem for Ricci-inverse Gravity?
Indranil Das, Joseph P Johnson, S. Shankaranarayanan
Recently, Amendola et al. proposed a geometrical theory of gravity containing higher-order derivative terms. The authors introduced anticurvature scalar , which is the trace o…
Observational constraints and predictions of the interacting dark sector with field-fluid mapping
Joseph P Johnson, Archana Sangwan, S. Shankaranarayanan
We consider an interacting field theory model that describes the dark energy - dark matter interaction. Only for a specific interaction term, this interacting field theory descript…
Cosmological perturbations in the interacting dark sector: Mapping fields and fluids
Joseph P Johnson, S. Shankaranarayanan
There is no unique way to describe the dark energy-dark matter interaction, as we have little information about the nature and dynamics of the dark sector. Hence, in many of the ph…
Low-energy modified gravity signatures on the large-scale structures
Joseph P Johnson, S. Shankaranarayanan
A large number of dark energy and modified gravity models lead to the same expansion history of the Universe, hence, making it difficult to distinguish them from observations. To m…
Exact inflationary solutions in exponential gravity
Joseph P Johnson, Jose Mathew, S. Shankaranarayanan
We consider a modified gravity model of the form , where the strong gravity corrections are taken to all orders and is a self-interacting massless scalar…
Inflation with in Jordan frame
Jose Mathew, Joseph P Johnson, S. Shankaranarayanan
We consider an action that is non-minimally coupled to a massive scalar field. The model closely resembles scalar-tensor theory and by conformal transformation can be transf…