Towards plasma-like collisionless trajectories in the brain

Plasma Sources Science and Technology, 2010

In complex plasmas together with single particle behavior the study of collective phenomena in large assemblies is an important development. We analyze the interaction among particles in plasma in several cases, starting from clusters consisting of a few particles up to large assemblies. In some cases the formation of the self-built electric field at the edge of the cluster and the screening of an external electric field by the dust cloud are predicted. In the case of small clusters the formation of double layers at the edge of a cluster is considered. The dimension of the cluster plays a role. The competition for charge is crucial in explaining agglomeration of mesoscopic particles. Larger particles, of the size of a Debye length, agglomerate mainly because of the ion 'shadow' force, a small scale aspect of the self-built field. Experiments with an expansion of dust clusters in an external plasma sheath seem to prove the existence of the self-built electric field at the edge of the cloud and the screening of external sheath fields. Other experiments, such as formation of bubbles, lanes, electrorheological properties and 2D dislocations in crystals, enlarge the investigations on collective effects and show their importance in complex plasmas.

Arxiv preprint physics/0303022, 2003

This paper summarises an investigation of discreteness effects and the continuum limit for timeindependent, nearly collisionless N -body systems of charged particles interacting via an unscreened 1/r 2 force, allowing for bulk density distributions corresponding to potentials that admit both regular and chaotic orbits. Both for orbit ensembles and for individual orbits, for N → ∞ there is a smooth convergence towards a continuum limit. At least for moderately large values of N discreteness effects are extremely well modeled by Gaussian white noise with energy relaxation time tR, and hence diffusion constant D, consistent with the scaling tR ∝(N/ ln Λ)tD, with Λ the Coulomb logarithm and tD a natural 'dynamical' time scale, as predicted by a Fokker-Planck description. Discreteness effects accelerate emittance growth for an initially localised ensemble of orbits ('clump'). However, even allowing for discreteness effects one can distinguish clearly between orbits which, in the continuum limit, feel a regular (nonchaotic) potential, so that emittance grows as a power law in time, and chaotic orbits, for which the emittance grows exponentially. For sufficiently large N , one can implement a clear distinction between two different 'kinds' of chaos acting in N -body systems. Short range microchaos, associated with close encounters between individual charges, is a generic feature of the N -body problem, giving rise to large positive Lyapunov exponents χN which do not decrease with increasing N even if the bulk potential is integrable. Alternatively, there is the possibility of larger scale macrochaos, characterised typically by somewhat smaller Lyapunov exponents χS, which will be present only if the bulk potential admits global stochasticity. Conventional computations of the largest Lyapunov exponent provide estimates of χN , leading to the oxymoronic conclusion that N -body orbits which look nearly regular and have sharply peaked Fourier spectra are 'very chaotic.' However, the 'range' of the microchaos is set by the typical interparticle spacing which, as N increases, becomes progressively smaller, so that, for sufficiently large N , this microchaos, albeit very strong, is largely irrelevant macroscopically. A more careful numerical analysis allows one to derive estimates of both χN and χS.

Physical Review

A theory of electron oscillations of an unbounded plasma of uniform ion density is developed, taking into account the effects of random thermal motions, but neglecting collisions.

We calculate the energy of a homogeneous one component plasma and find that the energy is lower for correlated motions of the particles as compared to uncorrelated motion. Our starting point is the conserved approximately relativistic (Darwin) energy for a system of electromagnetically interacting particles that arises from the neglect of radiation. For the idealized model of a homogeneous one component plasma the energy only depends on the particle canonical momenta and the vector potential. The vector potential is then calculated in terms of the canonical momenta using recent theoretical advances and the plasma Hamiltonian is obtained. The result can be understood either as due to the energy lowering caused by the attraction of parallel currents or, alternatively, as due to the inductive inertia associated with the flow of net current.

academia.edu, 2025

We propose a novel framework for understanding consciousness as a recursive harmonic phenomenon embedded within plasma systems. Drawing from plasma physics, cymatics, archaeoastronomy, and recursion theory, we argue that certain plasma behaviors—particularly filamentation, toroidal formation, and double-layer self-organization—are indicative of intelligent field dynamics. We integrate evidence from ancient symbolic systems, scalar harmonic models, and recent discoveries in plasma self-organization to suggest that plasma may not only carry information but exhibit field-level cognition.

Physics Letters A, 2001

Effects induced by the finite number N of particles on the evolution of a monochromatic electrostatic perturbation in a collisionless plasma are investigated. For growth as well as damping of a single wave, discrete particle numerical simulations show a N -dependent long time behavior which differs from the numerical errors incurred by vlasovian approaches and follows from the pulsating separatrix crossing dynamics of individual particles. Keywords : plasma kinetic theory wave-particle interaction self-consistent field particle motions and dynamics PACS numbers : 05.20.Dd (Kinetic theory) 52.35.Fp (Plasma: electrostatic waves and oscillations) 52.65.-y (Plasma simulation) 52.25.Dg (Plasma kinetic equations)

Physics of Plasmas, 1999

To better understand long time transport dynamics, techniques to investigate long-range dependences in plasma fluctuations have been applied to data from several confinement devices including tokamaks, stellarators, and reversed field pinch. The results reveal the self-similar character of the edge plasma fluctuations. This implies that the tail of the autocorrelation function decays as a power law and suggests that there is a superdiffusive component of the anomalous transport. Rescaled fluctuation and turbulent flux spectra from different devices also show a strong similarity. For a range of parameters corresponding to the tokamak ohmic regime and equivalent power for other devices, the spectral decay index may show a universal character.

Physics of Life Reviews, 2006

Neural activity patterns related to behavior occur at many scales in time and space from the atomic and molecular to the whole brain. Patterns form through interactions in both directions, so that the impact of transmitter molecule release can be analyzed upwardly through synapses, dendrites, neurons, populations and brain systems to behavior, and control of that release can be described step-wise through top-down transformations. Here we explore the feasibility of interpreting neurophysiological data in the context of many-body physics by using tools that physicists have devised to analyze comparable hierarchies in other fields of science. We focus on a mesoscopic level that offers a multi-step pathway between the microscopic functions of neurons and the macroscopic functions of brain systems revealed by hemodynamic imaging. We use electroencephalographic (EEG) records collected from high-density electrode arrays fixed on the epidural surfaces of primary sensory and limbic areas in rabbits and cats trained to discriminate conditioned stimuli (CS) in the various modalities. High temporal resolution of EEG signals with the Hilbert transform gives evidence for diverse intermittent spatial patterns of amplitude (AM) and phase modulations (PM) of carrier waves that repeatedly re-synchronize in the beta and gamma ranges at near zero time lags over long distances. The dominant mechanism for neural interactions by axodendritic synaptic transmission should impose distance-dependent delays on the EEG oscillations owing to finite propagation velocities. It does not. EEGs instead show evidence for anomalous dispersion: the existence in neural populations of a low velocity range of information and energy transfers, and a high velocity range of the spread of phase transitions. This distinction labels the phenomenon but does not explain it. In this report we explore the analysis of these phenomena using concepts of energy dissipation, the maintenance by cortex of multiple ground states corresponding to AM patterns, and the exclusive selection by spontaneous breakdown of symmetry (SBS) of single states in sequences.

Mathematical Theory and Modeling, 2013

The charged particles' action of E and B fields have three diverse levels of modeling, Starting with the simplest one to the most complicated. In this paper we consider the generalization of Newtonian force law in geometrical term is to describe charged particles' (plasma) trajectories on electromagnetic fields in the kinetic or microscopic model.