359 citations · 563 across the 17 of their papers we have counts for
17 papers
Probing Kinematic Anisotropies in the Stochastic Gravitational Wave Background with the SKA
N. M. J. Cruz, Ameek Malhotra, Gianmassimo Tasinato +1
Pulsar Timing Arrays (PTAs) and astrometric surveys provide complementary probes of the nanohertz stochastic gravitational-wave background (SGWB). A primary target is the kinematic…
Data-Driven Discovery of a Simple Phantom-Crossing Dark Energy Parametrization
Giulia Borghetto, Ameek Malhotra, Simran Arora +4
We develop a data-driven reconstruction programme for the dark-energy equation of state within VCDM, a minimally modified gravity framework in which both background and linear pert…
Bayesian optimisation for Bayesian evidence (BOBE) -- a fast and efficient likelihood emulator for model selection
Nathan Cohen, Jan Hamann, Ameek Malhotra
The formalism of Bayesian model selection provides a very elegant way of ranking different physical models in terms of how compatible they are with a given set of observed data. Ho…
Bayesian reconstruction of primordial perturbations from induced gravitational waves
Aya Ghaleb, Ameek Malhotra, Gianmassimo Tasinato +1
The formation of primordial black holes or other dark matter relics from amplified density fluctuations in the early universe may also generate scalar-induced gravitational waves (…
Bounded Dark Energy
Giulia Borghetto, Ameek Malhotra, Gianmassimo Tasinato +1
Recent cosmological observations suggest that the dark energy equation of state may have changed in the latter stages of cosmic history. We introduce a quintessence scenario, terme…
Astrometry meets Pulsar Timing Arrays: Synergies for Gravitational Wave Detection
N. M. Jiménez Cruz, Ameek Malhotra, Gianmassimo Tasinato +1
High-precision astrometry offers a promising approach to detect low-frequency gravitational waves, complementing pulsar timing array (PTA) observations. We explore the response of…
Cosmological tests of quintessence in quantum gravity
Sukannya Bhattacharya, Giulia Borghetto, Ameek Malhotra +3
We use a suite of the most recent cosmological observations to test models of dynamical dark energy motivated by quantum gravity. Specifically, we focus on hilltop quintessence sce…
A novel probe of graviton dispersion relations at nano-Hertz frequencies
Bill Atkins, Ameek Malhotra, Gianmassimo Tasinato
We generalise Phinney's 'practical theorem' to account for modified graviton dispersion relations motivated by certain cosmological scenarios. Focusing on specific examples, we sho…
Measuring the circular polarization of gravitational waves with pulsar timing arrays
N. M. Jiménez Cruz, Ameek Malhotra, Gianmassimo Tasinato +1
The circular polarization of the stochastic gravitational wave background (SGWB) is a key observable for characterising the origin of the signal detected by Pulsar Timing Array (PT…
Cosmological constraints on curved quintessence
Sukannya Bhattacharya, Giulia Borghetto, Ameek Malhotra +3
Dynamical dark energy has gained renewed interest due to recent theoretical and observational developments. In the present paper, we focus on a string-motivated dark energy set-up,…
Measuring kinematic anisotropies with pulsar timing arrays
N. M. Jiménez Cruz, Ameek Malhotra, Gianmassimo Tasinato +1
Recent Pulsar Timing Array (PTA) collaborations show strong evidence for a stochastic gravitational wave background (SGWB) with the characteristic Hellings-Downs inter-pulsar corre…
New universal property of cosmological gravitational wave anisotropies
Ameek Malhotra, Ema Dimastrogiovanni, Guillem Domènech +2
The anisotropies of the stochastic gravitational wave background, as produced in the early phases of cosmological evolution, can act as a key probe of the primordial universe parti…
Constraining primordial tensor features with the anisotropies of the Cosmic Microwave Background
Jan Hamann, Ameek Malhotra
It is commonly assumed that the stochastic background of gravitational waves on cosmological scales follows an almost scale-independent power spectrum, as generically predicted by…
Enhancing gravitational wave anisotropies with peaked scalar sources
Ema Dimastrogiovanni, Matteo Fasiello, Ameek Malhotra +1
Gravitational wave (GW) backgrounds of cosmological origin are expected to be nearly isotropic, with small anisotropies resembling those of the cosmic microwave background. We anal…
Cosmology with the Laser Interferometer Space Antenna
Pierre Auclair, David Bacon, Tessa Baker +177
The Laser Interferometer Space Antenna (LISA) has two scientific objectives of cosmological focus: to probe the expansion rate of the universe, and to understand stochastic gravita…
Testing the Early Universe with Anisotropies of the Gravitational Wave Background
Ema Dimastrogiovanni, Matteo Fasiello, Ameek Malhotra +2
In this work we analyse in detail the possibility of using small and intermediate-scale gravitational wave anisotropies to constrain the inflationary particle content. First, we de…
Cross-correlations as a Diagnostic Tool for Primordial Gravitational Waves
Ameek Malhotra, Ema Dimastrogiovanni, Matteo Fasiello +1
We explore and corroborate, by working out explicit examples, the effectiveness of cross-correlating stochastic gravitational wave background anisotropies with CMB temperature fluc…