Seminars and Lectures
Talk at Winter Seminar, Dolni Morava
The magnetopause is the boundary where the solar wind and magnetosphere balance the other's pressure. Once the upstream solar wind conditions change, the magnetopause moves to a new position and changes its shape accordingly. Previous studies usually calculate the magnetopause moving speed by using two crossings close in location and time. However, such events are relatively rare. A new hypothesis suggests using the ion speed in the magnetopause layers to estimate the magnetopause moving speed. As a boundary that plasma can not pass through, the ion speed in the magnetopause should related to the magnetopause moving speed. This study aims to check whether this hypothesis is correct by using numerous magnetopause crossings recorded by THEMIS mission. The magnetopause moving speed is calculated using the traditional method and compared with the results estimated using the new method.
Poster Presentation at Acharya Prafulla Chandra College, WBSU
In this paper, we consider a dense stellar plasma consisting of predominantly electrons, positrons, and ions under the action of the magnetic field of the star. We derived the KDV Burgers equations by using the reductive perturbation technique and obtained shock and solitary profiles for magnetoacoustic waves. We further studied the self-interaction of such stationary formations and the amplitude-modulated envelope solitons. The possibility of a rogue wave-like structure is also discussed. To understand the physical problem in greater detail, we studied the Hamiltonian formulation to study the stability. We studied how modulational instability can lead to the formation of rogue waves by investigating the non-linear Schrodinger equation. Additionally, drift-like instability showing the density and charge separation effects in plasma has been studied. The results will be helpful to interpret magnetoacoustic wave formations in solar corona, or other stellar entities and can help in the study of inhomogeneous plasmas in laboratory and fusion reactors.
Masters Thesis Lecture at Acharya Prafulla Chandra College, WBSU
The inflow of matter towards a central gravitating object or towards the center of mass of an extended system is known as accretion. In the early solar system, gravity caused small particles, dust, and gases to collect and combine into larger and larger objects. The process of accretion involves pulling nearby matters towards them due to the gravitational attraction of massive objects. Accretion is also responsible for gathering clouds of hydrogen to stars and stars to galactic disks. Transonic accretion flow is the only physically accepted condition of black hole accretion as the flow must be subsonic at an infinite distance away from the black hole and supersonic at the event horizon.
Talk at Acharya Prafulla Chandra College, WBSU
This talk was about nonlinear dynamics. The history dates back to 1666. Newton solved the two-body problem by considering the sun and a planet but he could not solve it for three bodies. Later in 1800, Poincare proved with his geometrical interpretation that three body problem is not solvable. Henry Poincare was the first one to give the concept of chaos. Between the 1920-50s nonlinear oscillations were studied extensively. Later in the 1950s, the computer was invented and suddenly the whole nonlinear dynamics became way easy. In 1960, Lorenz studied the atmosphere and He gave a chaotic system in a model of convection in the atmosphere. Moreover, the first nonlinear system that we have studied is the "simple pendulum". If we plot the phase trajectories of the motion of a simple pendulum and if the initial conditions are changed then the result changes drastically. The population growth/decay of an organism can be studied using nonlinear dynamics. Whatever we see in day to day to life is in many cases nonlinear and also chaotic. From a simple pendulum wall clock to the clouds and finally, to the planets and their problems, everything follows nonlinear dynamics.
Poster for Presision 2020 Final.pdfPoster Presentation at Presision 2020
In this poster, we consider the propagation of electron acoustic solitary waves in semi-classical plasma. Using the quantum hydrodynamic model we obtain the dispersion relation and study the parametric variations of the dispersion curve. We further study the solitary profiles and their evolution by using the Korteweg-de Vries Burger equation. We extended our work to the study of Rogue waves. The results provide interesting findings that have laboratory and astrophysical imports.
Website : https://presision20.weebly.com/poster-presentation.html
Last Talk of the Evening ...
This was my First Online Talk...
Talk at Behala College, University of Calcutta
I was thrilled to have the chance to share my knowledge of physics and its application in music with the audience at Behala college in my first year of my bachelor’s degree at Calcutta university. I explained the physics behind pluck string, struck string instruments, and beats in the lecture. Though it was my first talk, but the enthusiasm of the audience made me feel truly inspired as I spoke about the physics behind music. From the feedback that I received, it was clear that the lecture had enabled them to better understand the intricate relationship between physics and music. It was exciting to be able to take a complex concept like physics behind music and break it down into something easier to comprehend. Additionally, I enjoyed being able to answer questions from the audience during the lecture, as it gave me an opportunity to further explore my knowledge. I am grateful for having had the chance to present such an interesting topic as part of my curriculum at my university. It has been an incredible experience and I am thankful to all. This experience has inspired me to further explore this fascinating topic and make more informative lectures on the subject in the future.
I want to Thank my Guruji Pandit Manoj Shankar Ji who is my inspiration. I had taken 'talem' from Him from a very early age. Although Guruji is no longer with us, his teachings and devotion to music will continue to exist among his admirers.