Pallavi Bhat

Pallavi Bhat

Profile

I am currently a postdoc research fellow at the Department of Applied Mathematics, University of Leeds. I joined in Feb 2019.

My two previous postdoc experiences were at PSFC, Massachusetts Institute of Technology  (2016-2018) and PPPL, Princeton University (2015-2016). At MIT, I worked on magnetic reconnection and at Princeton, I worked on magnetorotational instability and the dynamo connection.

I obtained my PhD in 2015 on the topic of "Magnetic fields in the universe: their origin and evolution" under the guidance of Prof. Kandaswamy Subramanian at Inter-University Center for Astronomy and Astrophysics (IUCAA), India.

 

 

Research interests

I work in the field of plasma/fluid astrophysics applied to the Sun, stars, galaxies, galaxy-clusters, accretion disks. The following an overview of the different topics in fluid/plasma dynamics that I have worked on – 

Dynamo Theory:

The coherent magnetic fields observed in most astrophysical systems like the Sun, stars, galaxies and even galaxy-clusters is thought to be generated and maintained by turbulent dynamo action. I have been studying the dynamo theory and its application to these turbulent astrophysical systems. My previous work consists of both analytics and simulations. I have worked on generalizing theory of small-scale dynamos to finite time correlation. I have studied large resolution (10243) simulations of small and large-scale dynamos and tried to understand their dynamics via statistical analysis and also understanding the signature of these magnetic fields in observables like Faraday rotation measure etc. 

Magneto-rotational instability (MRI) and dynamo connection:

MRI is required to provide for angular momentum transport in accretion disks at rates consistent with that inferred from observations. Also needed in accretion discs are large-scale magnetic fields for forming jets and nonlocal transport of angular momentum. Using shearing box simulations of MRI, I have studied the growth of large-scale fields in the system. 

Magnetic reconnection

My most recent explorations involve studying magnetic reconnection and one of its important manifestation known as the plasmoid instability. Magnetic reconnection involves a rapid topological rearrangement of the magnetic field, leading to efficient magnetic energy conversion and dissipation. They are thought to be the cause of many violent events on the surface of the sun like solar flares. Theoretically, besides the steady-state models of reconnection,  I have studied the tearing mode instability theory in MHD. In particular, I have researched the nature of reconnection in a kinetic plasma regime known as the semi-collisional regime. My studies make a connect with recent experiments as this regime allows for plasmoid instability to occur at much lower Lundquist numbers as opposed to the MHD case. 

More recently I have been happy to talk about my work on quasi-kinematic large-scale dynamo in a large Reynolds number system and also applying magnetic reconnection to understand inverse cascades in decaying nonhelical turbulence. 

Currently, at Leeds, I am investigating some nonlinear aspects of turbulent dynamos involving helicity fluxes. 

Qualifications

  • Ph.D. (2015)