Natarajan’s intellectual style in her research involves the generation of novel ideas and new methods that permit direct comparison and confrontation of theoretical models to observational data to answer fundamental questions in astrophysics. She adopts a unique systems approach to problem solving that consists of parsing a complex problem and paring it down to make them tractable. While her mainstay is model-building, she is deeply invested in validating them with empirical data and the analysis of numerical simulations. Her research interests span the following areas and she tackles the many key open questions therein.
GRAVITATIONAL LENSING
Methods and techniques to combine strong and weak lensing analysis to constrain the nature of dark matter and dark energy; the reconstruction of mass distributions; high-resolution dark matter mapping; confronting lensing observations with theoretical predictions from simulations; lensing and lens statistics as a probe cosmology; the properties of the lens as well as studies of the background faint population brought into view by lensing – their abundance and role in re-ionizing the universe; lensing tests of the underlying cosmological model.
CLUSTERS OF GALAXIES AS ASTROPHYSICAL LABORATORIES
Dynamical processes that shape their evolution – ram pressure stripping and tidal stripping in cluster environments; studies of the assembly of clusters in cosmological simulations; properties of cluster galaxies and their evolution; cosmography with clusters to use clusters as probes of the underlying cosmological model and characterization of the equilibrium states of clusters.
BLACK HOLE PHYSICS
The physics of accretion – angular momentum transfer, alignment of spins, properties of accretion disks – warps; modeling the growth history of black holes over cosmic time; formation of seed black holes; properties of direct collapse black hole seeds; co-evolution of black holes and their host galaxies; AGN feedback – physical processes that couple small and large scales; quasar outflows; the formation of inter-mediate mass black holes; fate of black holes in galaxies; the accretion history of supermassive and ultra-massive black holes and channels for amplifying black hole mass growth; tidal disruption events by single central and binary black holes; observational signatures of the tidal stripping of the first stars.
BINARY BLACK HOLES
The role of gas and accretion disks in effecting binary black hole mergers; the merger and evolution of supermassive black hole binaries in gas-rich galaxy cores; the electro-magnetic and gravitational wave signatures from these systems; the evolution of eccentricity in binary black hole mergers; multi-messenger signatures of merging black holes – gravitational waves and electromagnetic counter-parts
ISSUES IN GALAXY FORMATION
The connection between high redshift galaxies, relationship between star formation and AGN activity; the nature of energy injection and feedback from supernovae and AGN; co-evolution of AGN and their central black holes; gamma-ray bursts and their host galaxies and their use as cosmological probes; the origin of correlations between black holes and their hosts; role of quasars, their outflows and impact/fate of gas in feedback; kinematic Sunyaev-Zeldovich effect from quasars; formation of dwarf galaxies from quasar outflows.
HISTORY & PHILOSOPHY OF SCIENCE
Foundational questions in epistemology – nature of knowledge production and inference in science in the absence of controlled experiments; the nature of causation, correlation and the role of models and simulations in inference.