Strong B-Field Fluctuations Caused by the Electromagnetic LHDI and their Impact on 3D Reconnection

Abstract

<p>The electromagnetic branch of the lower-hybrid drift instability (LHDI) can lead to kinking of current sheets and fluctuations in the magnetic field and is present for example in Earth’s magnetosphere. Previous particle-in-cell studies suggested that the electromagnetic LHDI’s saturation is at a moderate level and that strong current sheet kinking is only caused by slower kink-type modes. Here, we present kinetic continuum simulations that show strong kinking and high saturation levels of the B-field fluctuations. Has the impact of the electromagnetic LHDI been underestimated? The capability of the LHDI to produce x-lines and turbulence in 3D reconnection is discussed at the example of ten-moment multi-fluid simulations.</p>

A quantum-inspired method for solving the Vlasov-Poisson equations

“…The Vlasov equation, a 6-D nonlinear partial differential equation (PDE), provides an ab-initio description of the dynamics of such plasmas and is deemed to be the gold standard in plasma simulation. It can be solved deterministically using Eulerian [1][2][3][4][5] or semi-Lagrangian [6][7][8][9][10][11][12][13][14] grid-based methods. Unlike the alternative particle-in-cell (PIC) approach [15][16][17][18][19][20][21][22], these methods do not suffer from stochastic noise issues; however, they are extremely computationally expensive thanks to the exponential scaling of cost with respect to dimensionality and the resolution requirements stemming from the multi-scale dynamics that characterizes the vast majority of nonlinear plasma behavior.…”

“…Formally, one choice of MPS ansatz is equivalent to the tensor train representation, in which the data is decomposed into a series of tensors each corresponding to one of its dimensions, and then compressed by limiting the rank (the correlations) between each dimension. Tensor trains have been employed to solve PDEs in a variety of contexts ranging from fluid dynamics to molecular electronic structure [30][31][32][33], including the Vlasov-Poisson and Vlasov-Maxwell equations in up to 6-D space [13,14,[34][35][36][37]. However, the intended MPS ansatz mirrors that of quantized tensor trains [38][39][40], in which the data is decomposed into smaller components such that one can limit the correlations within each dimension as well.…”