297 citations · 416 across the 23 of their papers we have counts for
24 papers
Physics-Informed Kolmogorov-Arnold Networks for Grad-Shafranov Tokamak Equilibria
D. A. Kaltsas, A. Kuiroukidis, J. Liu +2
We employ equation-driven, physics-constrained deep learning to solve the fixed-boundary Grad-Shafranov (GS) equilibrium problem, constructing axisymmetric magnetohydrodynamic equi…
Imposing quasineutrality on electrostatic plasmas via the Dirac theory of constraints
D. A. Kaltsas, J. W. Burby, P. J. Morrison +2
We present a method for imposing quasineutrality and, more generally, charge density conservation in the Vlasov-Poisson (VP) and Vlasov-Ampère (VA) systems, which describe electros…
Hybrid fluid-kinetic cylindrical equilibria with axial background magnetic field
D. A. Kaltsas, A. I. Kuiroukidis, G. N. Throumoulopoulos
Self-consistent, one-dimensional quasineutral screw-pinch equilibria are constructed within a hybrid model that couples fluid electrons with kinetic ions governed by the Vlasov equ…
Hamiltonian formulation of the quasineutral Vlasov-Poisson system
J. W. Burby, D. A. Kaltsas, P. J. Morrison +2
Slow manifold reduction and the theory of Poisson-Dirac submanifolds are used to deduce a Hamiltonian formulation for a quasineutral limit of the planar, collisionless, magnetized…
New axisymmetric equilibria with flow from an expansion about the generalized Solov'ev solution
A. I. Kuiroukidis, D. A. Kaltsas, G. N. Throumoulopoulos
We construct analytic solutions to the generalized Grad-Shafranov equation, which incorporates both toroidal and poloidal flows. This is achieved by adopting a general linearizing…
Multi-soliton solutions and data-driven discovery of higher-order Burgers' hierarchy equations with physics informed neural networks
D. A. Kaltsas, L. Magafas, P. Papadopoulou +1
The Burgers hierarchy consists of nonlinear evolutionary partial differential equations (PDEs) with progressively higher-order dispersive and nonlinear terms. Notable members of th…
Constrained Hamiltonian Systems and Physics-Informed Neural Networks: Hamilton-Dirac Neural Networks
Dimitrios A. Kaltsas
The effectiveness of the Physics Informed Neural Networks (PINNs) for learning the dynamics of constrained Hamiltonian systems is demonstrated using the Dirac theory of constraints…
A similarity reduction of the generalized Grad-Shafranov equation
A. I. Kuiroukidis, D. A. Kaltsas, G. N. Throumoulopoulos
We extend previous work [Y. E. Litvinenko, Phys. Plasmas 17, 074502 (2010)] on a direct method for finding similarity reductions of partial differential equations such as the Grad-…
Analytic Hall Magnetohydrodynamics toroidal equilibria via the energy-Casimir variational principle
A. Giannis, D. A. Kaltsas, G. N. Throumoulopoulos
Equilibrium equations for magnetically confined, axisymmetric plasmas are derived by means of the energy-Casimir variational principle in the context of Hall magnetohydrodynamics (…
Chaotic and integrable magnetic fields in one-dimensional hybrid Vlasov-Maxwell equilibria
Dimitrios A. Kaltsas, Philip J. Morrison, George N. Throumoulopoulos
In this paper, we develop a one-dimensional (1-D), quasineutral, hybrid Vlasov-Maxwell equilibrium model with kinetic ions and massless fluid electrons and derive associated soluti…
Robustness versus sensitivity in non-Hermitian topological lattices probed by pseudospectra
I. Komis, D. Kaltsas, S. Xia +3
Non-Hermitian topological systems simultaneously posses two antagonistic features: ultra sensitivity due to exceptional points and robustness of topological zero energy modes, and…
Neural network tokamak equilibria with incompressible flows
D. A. Kaltsas, G. N. Throumoulopoulos
We present several numerical solutions to a generalized Grad-Shafranov equation (GGSE), which governs axisymmetric plasma equilibria with incompressible flows of arbitrary directio…
Hamiltonian kinetic-Hall Magnetohydrodynamics with fluid and kinetic ions in the current and pressure coupling schemes
D. A. Kaltsas, G. N. Throumoulopoulos, P. J. Morrison
We present two generalized hybrid kinetic-Hall magnetohydrodynamics (MHD) models describing the interaction of a two-fluid bulk plasma, which consists of thermal ions and electrons…
Nonlinear control of PT-symmetry and non-Hermitian topological states
Shiqi Xia, Dimitrios Kaltsas, Daohong Song +6
Advances in topological photonics and non-Hermitian optics have drastically changed our perception on how interdisciplinary concepts may empower unprecedented applications. Bridgin…
A tokamak pertinent analytic equilibrium with plasma flow of arbitrary direction
D. A. Kaltsas, A. Kuiroukidis, G. N. Throumoulopoulos
An analytic solution to a generalized Grad-Shafranov equation with flow of arbitrary direction is obtained upon adopting the generic linearizing ansatz for the free functions relat…
A discrete Nambu bracket for 2D extended Magnetohydrodynamics
D. A. Kaltsas, M. Kraus, G. N. Throumoulopoulos
In this note we propose a trilinear bracket formulation for the Hamiltonian extended Magnetohydrodynamics (XMHD) model with homogeneous mass density. The corresponding two-dimensio…
Energy-Casimir, dynamically accessible, and Lagrangian stability of extended magnetohydrodynamic equilibria
D. A. Kaltsas, G. N. Throumoulopoulos, P. J. Morrison
The formal stability analysis of Eulerian extended magnetohydrodynamics (XMHD) equilibria is considered within the noncanonical Hamiltonian framework by means of the energy-Casimir…
2D magnetofluid models constructed by a priori imposition of conservation laws
D. A. Kaltsas, G. N. Throumoulopoulos
Motivated by a geometric method employed for the derivation of the Nambu bracket for ideal two-dimensional incompressible hydrodynamics, we reconstruct the reduced magnetohydrodyna…
Ellipticity conditions for the extended MHD Grad-Shafranov-Bernoulli equilibrium equations
D. A. Kaltsas, G. N. Throumoulopoulos, P. J. Morrison
In this study, we find the points of transition between elliptic and hyperbolic regimes for the axisymmetric extended magnetohydrodynamic (MHD) equilibrium equations. The elliptici…
A generalized Grad-Shafranov equation with plasma flow under a conformal coordinate transformation
A. Kuiroukidis, D. Kaltsas, G. N. Throumoulopoulos
We employ a conformal mapping transformation to solve a generalized Grad-Shafranov equation with incompressible plasma flow of arbitrary direction and construct particular up-down…
Certain developments on the equilibrium of magnetized plasmas
A. Evangelias, D. A. Kaltsas, A. Kuiroukidis +3
Recent results will be presented on steady states of magnetically confined plasmas obtained by conventional and Hamiltonian methods. The presentation consists of three parts. The f…
Helically symmetric extended magnetohydrodynamics: Hamiltonian formulation and equilibrium variational principles
D. A. Kaltsas, G. N. Throumoulopoulos, P. J. Morrison
Hamiltonian extended magnetohydrodynamics (XMHD) is restricted to respect helical symmetry by reducing the Poisson bracket for 3D dynamics to a helically symmetric one, as an exten…
Translationally symmetric extended MHD via Hamiltonian reduction: Energy-Casimir equilibria
D. A. Kaltsas, G. N. Throumoulopoulos, P. J. Morrison
The Hamiltonian structure of ideal translationally symmetric extended MHD (XMHD) is obtained by employing a method of Hamiltonian reduction on the three-dimensional noncanonical Po…
Exact solutions of the Grad-Shafranov equation via similarity reduction and applications to magnetically confined plasmas
Dimitrios A. Kaltsas, George N. Throumoulopoulos
We derive exact solutions of a linear form of the Grad-Shafranov (GS) equation, including incompressible equilibrium flow, using ansatz-based similarity reduction methods. The line…