We show that the dark matter halos of the Clouds are significantly distorted, wherein the density field can deviate by ~60% relative to a spherical halo.

The mutual LMC-SMC interactions have significantly distorted their dark matter distributions. Modeling their complex dark matter distribution is important for accurately inferring the LMC-SMC interaction history as well as the orbits of the satellite galaxies associated with the Clouds. In Foote,Rathore+2026, we use basis function expansions on a state-of-the-art simulation of the LMC-SMC interaction history to map the Clouds' dark matter distribution. We also identify halo dynamical signatures that are applicable to a wide class of interacting galaxies.

We show that the LMC hosts a strong bar, consistent with the expectation of bar-galaxy co-evolution.

The LMC has a strange bar. The bar is offset from the disk center, tilted with the disk plane and does not drive gas inflows. In Rathore+2025(a), we used Gaia DR3 data to measure the geometry and strength of the LMC's bar with the stellar density field. To perform this measurement, we developed a novel solution to tackle crowding induced incompleteness in Gaia datasets.




Why does the LMC's bar show such strange properties despite being consistent with bar - galaxy co-evolution ?

The LMC bar's strange properties are explainable with a recent direct collision between the LMC & SMC. Excitingly, the bar's tilt is a direct probe of the SMC's dark matter content.

In Rathore+2025(b), we use hydrodynamical simulations to understand the response of the LMC's bar to a recent SMC collision. The SMC is responsible for the LMC bar's various strange properties, like its offset, tilt, lack of gas inflows and unusually low pattern speed. Further, the LMC bar's tilt is a direct consequence of the SMC's gravitational torques, and requires the SMC to be a dark matter dominated galaxy.

We find that star-forming S0 galaxies were likely quenched S0s in the past, whose star-formation has been rejuvenated possibly through minor mergers.

S0 galaxies possess well defined disks, but lack spiral arms and are generally expected to be quenched. Hence, the existence of star-forming S0s poses a challenge to galaxy evolution theories. In Rathore+2022, we performed a detailed study of star-forming S0s with resolved spectroscopic observations from the SDSS-MaNGA survey. Surprisingly, star-forming S0 galaxies possess centrally dominated star-formation, which is different from disk dominated star-formation in spiral galaxies. However, the star-forming S0s are structurally similar to quenched S0s.

We find that a 4% larger value of the Gravitational Constant at lookback times > 70 Million years is preferred by the Cepheid-Supernova data.

The Hubble tension is a raging debate in cosmology about the current expansion rate of the universe, as quantified by the Hubble constant. Early universe probes like the Cosmic Microwave Background and late universe probes like the Cepheid-Supernovae distance ladder give different values of the Hubble constant. One possible explaination for the Hubble tension is physics beyond general relativity, like a time varying gravitational constant (G). In Ruchika, Rathore et al. 2024, we carefully evaluate the effect of a G-transition on the Cepheid-Supernovae distance measurements.