9 papers
Wave interference as the origin of the cyclic magnetorotational dynamo in accretion disks: insights from weakly nonlinear theory and local shearing box simulations
Uddipan Banik, Amitava Bhattacharjee, James M. Stone
Long-period cyclic reversals of the large-scale magnetic field are a prominent feature of the dynamo associated with the magnetorotational instability (MRI) in accretion disks, but…
Non-thermal particle acceleration in multi-species kinetic plasmas: universal power-law distribution functions and temperature inversion in the solar corona
Uddipan Banik, Amitava Bhattacharjee
Non-thermal power-law distribution functions are ubiquitous in astrophysical, space, and laboratory kinetic plasmas, but their origin remains unclear. A related puzzle is the tempe…
Collisionless relaxation to equilibrium distributions in cold dark matter halos: origin of the Navarro-Frenk-White profile
Uddipan Banik, Amitava Bhattacharjee
Collisionless self-gravitating systems such as cold dark matter halos are known to harbor universal density profiles despite the intricate non-linear physics of hierarchical struct…
Not all cores are equal: Phase-space origins of dynamical friction, stalling and buoyancy
Shashank Dattathri, Frank C. van den Bosch, Uddipan Banik +4
Dynamical friction governs the orbital decay of massive perturbers within galaxies and dark matter halos, yet its standard Chandrasekhar formulation fails in systems with cores of…
Universal power-law distribution functions in an electromagnetic kinetic plasma: implications for the inverted temperature profile in the solar corona
Uddipan Banik, Amitava Bhattacharjee
We develop a self-consistent quasilinear theory for the relaxation of electromagnetic kinetic plasmas, and demonstrate that the mean distribution functions of both electrons and io…
A self-consistent quasilinear theory for collisionless relaxation to universal quasi-steady state attractors in cold dark matter halos
Uddipan Banik, Amitava Bhattacharjee
Collisionless self-gravitating systems, e.g., cold dark matter halos, harbor universal density profiles despite the intricate non-linear physics of hierarchical structure formation…