17 citations · 24 across the 18 of their papers we have counts for
19 papers
Divergence Without Transition in Adiabatic Theory: Exact Cancellation in Reflectionless Potentials
Amitava Bhattacharjee
Adiabatic invariants play a central role in plasma physics, from magnetic moment and bounce action to wave action in slowly varying media. Their perturbative constructions are ofte…
Optical analogy for stellarators: Ridges as caustics and coils as singularities
Wrick Sengupta, Stefan Buller, Rogerio Jorge +7
A common feature of most numerically optimized stellarator geometries is the presence of sharp ridges on outer flux surfaces, irrespective of the rotational transform. Despite thei…
Anderson Localization of Ion-Temperature-Gradient Modes in Aperiodic Stellarators
Amitava Bhattacharjee
The geometric coefficients of the ion-temperature-gradient (ITG) eigenmode equation along a magnetic field line are aperiodic because the line samples the full three-dimensional ge…
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…
System Size Dependence of Collisionless Reconnection Rate
Yi-Min Huang, Naoki Bessho, Li-Jen Chen +2
It is a widely accepted paradigm that collisionless magnetic reconnection proceeds at a universal fast rate of when normalized to a properly defined reconnecting magnetic…
Forced Reconnection in Voigt-Regularized MHD
Andrew Brown, Yi-Min Huang, Amitava Bhattacharjee
Forced reconnection in Voigt-regularized MHD is investigated in the Hahm-Kulsrud-Taylor problem. It is shown that Voigt regularization introduces an early linear phase of reconnect…
Topological Arrest of Ballooning Modes in Non-Axisymmetric Plasmas
Amitava Bhattacharjee
Why do non-axisymmetric stellarators avoid ballooning crashes that afflict tokamaks? Three-dimensional geometry induces Anderson localization of ballooning modes, converting a glob…
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…
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…
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…
The spectrum of magnetized turbulence in the interstellar medium
James R. Beattie, Christoph Federrath, Ralf S. Klessen +2
The interstellar medium (ISM) of our Galaxy is magnetized, compressible and turbulent, influencing many key ISM properties, like star formation, cosmic ray transport, and metal and…
Local relaxation and scale-dependent alignment in compressible, magnetized turbulence
James R. Beattie, Amitava Bhattacharjee
Driven net- and no-net-flux MHD turbulence simulations up to reveal sign-mixed velocity--magnetic, velocity--vorticity, and magnetic--current aligned patches below the…
Density fluctuation-Mach number scaling in compressible, high plasma beta turbulence: in-situ space observations and high-Reynolds number simulations
Riddhi Bandyopadhyay, James R. Beattie, Amitava Bhattacharjee
Understanding the nature of compressible fluctuations in a broad range of turbulent plasmas, from the intracluster medium to the solar wind, has been an active field of research in…
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…
Universal non-thermal power-law distribution functions from the self-consistent evolution of collisionless electrostatic plasmas
Uddipan Banik, Amitava Bhattacharjee, Wrick Sengupta
Distribution functions of collisionless systems are known to show non-thermal power law tails. Interestingly, collisionless plasmas in various physical scenarios, (e.g., the ion po…
Magnetized compressible turbulence with a fluctuation dynamo and Reynolds numbers over a million
James R. Beattie, Christoph Federrath, Ralf S. Klessen +2
Supersonic magnetohydrodynamic (MHD) turbulence is a ubiquitous state for many astrophysical plasmas. However, even the basic statistics for this type of turbulence remains uncerta…
Relaxation of weakly collisional plasma: continuous spectra, discrete eigenmodes, and the decay of echoes
Uddipan Banik, Amitava Bhattacharjee
The relaxation of a weakly collisional plasma, which is of fundamental interest to laboratory and astrophysical plasmas, can be described by the Boltzmann-Poisson equations with th…
Taking control of compressible modes: bulk viscosity and the turbulent dynamo
James R. Beattie, Christoph Federrath, Neco Kriel +2
Many polyatomic astrophysical plasmas are compressible and out of chemical and thermal equilibrium, introducing a bulk viscosity into the plasma via the internal degrees of freedom…
A model of solar equilibrium: the hydrodynamic limit
Lee Gunderson, Amitava Bhattacharjee
Helioseismology has revealed the internal density and rotation profiles of the Sun. Yet, knowledge of its magnetic fields and meridional circulation is confined much closer to the…