Research

White Dwarfs

White dwarfs (WDs) are compact stellar remnants that represent the final evolutionary stage of low mass stars in the Universe. In binary systems, accreting white dwarfs can develop strong magnetic fields, rapid rotation, and energetic plasma environments. My research focuses on how these extreme conditions can drive transient phenomena and coherent radio emission, making white dwarfs promising laboratories for high-energy astrophysics and thereby understand some other physics at this extremely dense environments.

Fast Radio Bursts

Fast Radio Bursts (FRBs) are brief, millisecond-duration flashes of radio waves originating from extragalactic distances. Their dispersion measures encode information about the ionized baryon content of the intergalactic medium, enabling constraints on cosmological parameters such as the baryon fraction, matter density, and the Hubble constant. My research aims to understand the physical mechanisms behind FRBs as well as their use to perform cosmological and physical parameter estimations, and test different cosmological models.

Gravitational Waves from WDs

Using a modified version of the publicly available XNS numerical code, we modeled rotating, magnetized white dwarfs and showed that with pulsar-like configurations, they emit both electromagnetic dipole and gravitational quadrupole radiation. Our results demonstrate that the emission timescales depend sensitively on the magnetic field geometry, allowing us to estimate detectability timescales for current and future gravitational wave (GW) detectors.

FRB Generation Mechanism

FRBs can be generated through Gertsenshtein-Zel’dovich (GZ) effect (when GWs traverse a pulsar magnetosphere, a portion of it is transformed into electromagnetic radiation). If GWs can be detected in the future from the location of FRBs, it will validate the GZ process for FRB production and can potentially rule out several other theories of FRB generation.

WDs under modified gravity

WDs under alternate theory of gravity can achieve its maximum mass below or above the Chandrasekhar mass limit.

Cosmology with FRBs

The localized FRBs align with different values of the Hubble constant at different redshift under standard Lambda-CDM comology.

Double WDs formation

The double WDs show a bimodality in their orbital separation due to difference in their formation pathways as well as their chemical composition and mass transfer rates.

Lensing with FRBs

Gravitational lensing with FRBs help in constraining fraction of primordial mass black holes comprised of dark matter, which further depend on underlying theory of gravity.

Fundamental Constant

With WDs and FRBs, we put constraints on the fine-structure constant, which depend on the underlying theory of gravity or the underlying cosmology; thus affected by the energy scale. There constraints have some of the strongest available in the literature.

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