51 citations · 261 across the 14 of their papers we have counts for
8 papers · 1 filter
Dynamical Dark Energy or Modified Gravity? Signatures in Gravitational Wave Propagation
Purnendu Karmakar, Sandeep Haridasu
We discuss the implications of the most recent DESI Baryon Acoustic Oscillations (BAO) DR2 and DESyr5 compilation of supernovae (SNe) datasets for modified gravity focusing on non-…
Cosmological evolution of viable models in the generalized scalar-tensor theory
Shun Arai, Purnendu Karmakar, Atsushi Nishizawa
We investigate the parameter distributions of the viable generalized scalar-tensor theory with conventional dust matter after GW170817 in a model-independent way. We numerically co…
Hamiltonian analysis of mimetic scalar gravity revisited
Alexander Ganz, Purnendu Karmakar, Sabino Matarrese +1
We perform the Hamiltonian analysis of several mimetic gravity models and compare our results with those obtained previously by different authors. We verify that for healthy mimeti…
Gravity in mimetic scalar-tensor theories after GW170817
Alexander Ganz, Nicola Bartolo, Purnendu Karmakar +1
We derive the most general mimetic scalar-tensor theory assuming a healthy "seed" action and accounting for the constraints on the speed of gravitational-wave propagation arising f…
Cosmic structures and gravitational waves in ghost-free scalar-tensor theories of gravity
Nicola Bartolo, Purnendu Karmakar, Sabino Matarrese +1
We study cosmic structures in the quadratic Degenerate Higher Order Scalar Tensor (qDHOST) model, which has been proposed as the most general scalar-tensor theory (up to quadratic…
Cosmological perturbations in mimetic Horndeski gravity
Frederico Arroja, Nicola Bartolo, Purnendu Karmakar +1
We study linear scalar perturbations around a flat FLRW background in mimetic Horndeski gravity. In the absence of matter, we show that the Newtonian potential satisfies a second-o…
Testing Unimodular Gravity
Pankaj Jain, Purnendu Karmakar, Subhadip Mitra +2
We consider models of gravitation that are based on unimodular general coordinate transformations (GCT). These transformations include only those which do not change the determinan…
Cosmological Perturbation Analysis in a Scale Invariant Model of Gravity
Pankaj Jain, Purnendu Karmakar, Subhadip Mitra +2
We consider a model for gravity that is invariant under global scale transformations. It includes one extra real scalar field coupled non-minimally to the gravity fields. In this m…