ACADEMIC

Two heavy objects orbiting each other will create ripples in the fabric of spacetime(this fabric is a mathematical description that helps visualize Einstein's theory, it isn't to be taken literally).  Artwork by Sandbox Studio, Chicago with Corinne Mucha

Binary systems with a Neutron star and a Main Sequence star can enter a 'common envelope' phase, during which the Main Sequence star enters its Red Giant phase, expanding to a size comparable to the orbital separation. Consequently, this leads to the Neutron star(secondary) undergoing an inward spiral towards the core of the Red Giant(primary), traversing through its envelope. Accretion onto the Neutron introduces asymmetries onto its surface, which give rise to gravitational waves. My work under the supervision of Dr. Luke Chamandy involves an analysis of the strength of GWs from such and other similar systems.

A mollweide projection a constant radius surface of a spherical dark matter halo. The color indicates the number density of galaxies in the halo, with red being densest.

My summer project under the supervision of Dr. Shadab Alam was focused on the simulation of mock dark matter halos, presumed to overlay galaxy clusters and groups. Our efforts involved incorporating important observational effects like redshift space distortions and gravitational redshifts, to ensure that our simulated halos closely resembled real observed data. The ultimate future objective is the development of 'Group Finder Algorithms' that utilize these simulated halos, to train our models to detect groups in actual survey data. Furthermore, these simulations can be useful in survey design and instrument calibration. Within this project, my specific task revolved around developing a methodology for visualizing the 3D simulated halos, enabling us to understand how different phenomena can lead to differences in observed and actual structure of the halo. 

The Einstein Cross Q2234+030. The Four objects that make up a cross in this image are actually different images of the same quasar, formed by the bending light around a massive body between the line of sight to the quasar. Image: NASA, ESA, and STScI

In my Astrophysics Course instructed by Prof. Luke Chamandy, I designed a website for Gravitational Lensing, the bending of light around massive objects. I have tried to make it accessible to 3rd/4th year undergraduate students. I have also discussed some recent work, and provided with links to open source resources that can be used to learn more about this phenomena. Feel free to contact me if you have any queries or suggestions!

A 3D simulation to visualize the cosmic web of galaxies and their cluster on a very large scale. Image: V.Springel, Max-Planck Institut für Astrophysik, Garching bei München 

Under the supervision of Dr. Nishikanta Khandai, I derived the Cosmological equations describing the universe's evolution, and demonstrated how different types of universes(say with only matter, or radiation, or both) evolve, depending on its composition. I produced plots for every possible general case, including, but not limited to the ones discussed in Barbara Ryden's book, my primary reference.

A visualization of a Jupiter like exoplanet very close to the host star, also called a "Hot Jupiter". Image: NASA/JPL-Caltech 

Recent observations of enhanced chromospheric activity on the surface of host stars with close-by giant planets suggest a possibility of a magnetic interaction between the planetary magnetic field with the coronal field. We investigated this phenomena, and extend the model proposed by A.F. Lanza (2008), which works for circular planetary orbits, to accommodate elliptical orbits.

Interface of silicon oil(top layer) and water(bottom layer), which is being heated centrally from the bottom, as observed by our Schlieren setup.

As part of our continuous Schlieren Project, me and R. Vasanth Kashyap utilised our setup to examine convection in liquids, specifically water, silicon oil, and their interface. By analysing the images obtained, we converted the intensity maps to refractive index maps and then to temperature maps. We observed some very interesting structures in the convection cells. You can check out the report by clicking on the image.

The air perturbations around a lighter flame made visible by our Schlieren Imaging setup

When light passes through any medium, it refracts and bends around it. This will introduce a change in an otherwise defined beam of light when it was simply passing through an even medium, compared to when it passes through a medium. It is possible to probe these tiny fluctuations in the beam by mean of a simply optical setup proposed by Schlieren. I and Vasanth Kashyap build this setup for our Open Lab Project.

The core and cladding of a optical fiber made visible by our Phase contrast setup. The center of the fiber would look opaque in simple white light.

A simple microscope, with a white light source, is useful in viewing colored samples, but it cannot differentiate between the different parts of a transparent sample or one that looks the same compared to its surrounding medium. A Phase Contrast Microscope uses the phase shifts of light to convert them to brightness changes in the observed image. In this experiment, I and R. Vasanth Kashyap built the first PCM of our lab, which will be added to the curriculum for coming batches. We have also discussed how this microscope, which is primarily used in Biology, can be used to observe some physics phenomena like the dynamics of bubbles in emulsions.

The Fourier transform image of a 2 dimensional grating(basically a 2D opaque grid with periodic holes in it)

Me and my labmate R. Vasanth Kashyap built a setup that can produce the Fourier transform image of any given image. If we again Fourier transform this Fourier transformed image, we know from the mathematics that we get back the original image. But if we filter out some of the Fourier image of the original image, and then let this filtered part be Fourier transformed, we can remove or enhance certain features of the original image. We can also use the Fourier images to develop more efficient ways of matching fingerprints for Forensic science. We demonstrated all these properties using our setup.