123 research outputs found

    On the physics of waves in the solar atmosphere: Wave heating and wind acceleration

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    In the area of solar physics, new calculations of the acoustic wave energy fluxes generated in the solar convective zone was performed. The original theory developed was corrected by including a new frequency factor describing temporal variations of the turbulent energy spectrum. We have modified the original Stein code by including this new frequency factor, and tested the code extensively. Another possible source of the mechanical energy generated in the solar convective zone is the excitation of magnetic flux tube waves which can carry energy along the tubes far away from the region. The problem as to how efficiently those waves are generated in the Sun was recently solved. The propagation of nonlinear magnetic tube waves in the solar atmosphere was calculated, and mode coupling, shock formation, and heating of the local medium was studied. The wave trapping problems and evaluation of critical frequencies for wave reflection in the solar atmosphere was studied. It was shown that the role played by Alfven waves in the wind accelerations and the coronal hole heating is dominant. Presently, we are performing calculations of wave energy fluxes generated in late-type dwarf stars and studying physical processes responsible for the heating of stellar chromospheres and coronae. In the area of physics of waves, a new analytical approach for studying linear Alfven waves in smoothly nonuniform media was recently developed. This approach is presently being extended to study the propagation of linear and nonlinear magnetohydrodynamic (MHD) waves in stratified, nonisothermal and solar atmosphere. The Lighthill theory of sound generation to nonisothermal media (with a special temperature distribution) was extended. Energy cascade by nonlinear MHD waves and possible chaos driven by these waves are presently considered

    MHD bending waves in a current sheet

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    Transverse MHD bending waves are considered in an isothermal and compressible two-dimensional current sheet of finite thickness in which the magnetic field changes direction and strength. The general form of the wave equation is obtained. It is shown that rotation of the magnetic field across the current sheet prevents the existence of singular points so that continuous spectrum solutions and the concomitant wave decay disappear. Instead, normal modes exist and closed integral solution for arbitrary current sheet structure are found. The results are discussed in terms of small-scale waves on the heliospheric current sheet

    New Fundamental Equation for Classical Waves and its Physical Applications

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    The irreducible representations of the extended Galilean group are used to derive the symmetric and asymmetric, in time and space derivatives, wave equations. It is shown that among these equations only a new asymmetric wave equation is fundamental. By being fundamental the equation gives the most complete description of propagating waves as it accounts for the Doppler effect, forward and backward waves, and makes the wave speed to be the same in all inertial frames. To demonstrate these properties, the equation is applied to acoustic waves propagation in an isothermal atmosphere. The derived fundamental wave equation plays the same role for classical waves as Newton's law of inertia plays for classical particles

    Atomic Model of Dark Matter Halo and Its Quantum Structure

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    A quantum theory of dark matter particles in a spherical halo is developed by using the new asymmetric equation, which appeared in [2021, Int. J. Mod. Phys. A, 36, 2150042]. The theory predicts that each dark matter halo has its core and envelope, which have very distinct physical properties. The core is free of any quantum structure and its dark matter particles are in random motion and frequently collide with each other. However, the envelope has a global quantum structure that contains quantized orbits populated by the particles. The predicted quantum structure of the halo resembles an atom, hence, it is here named the atomic model of dark matter halo. Applications of the theory to a dark matter halo with a given density profile are described, and predictions of the theory are discussed

    A New Look at the Quantum Measurement Problem

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    A novel solution to the measurement problem in quantum mechanics is proposed by using a new asymmetric equation, which is complementary to the Schr\"odinger equation. Since the latter describes evolution of the wavefunction, it is demonstrated that the new equation naturally describes collapse of the wavefunction. This implies that the full representation of the wavefunction in nonrelativistic quantum mechanics requires both equations

    Global and local cutoff frequencies for transverse waves propagating along solar magnetic flux tubes

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    The propagation of linear transverse waves along a thin isothermal magnetic flux tube is affected by a global cutoff frequency that separates propagating and non-propagating waves. In this paper, wave propagation along a thin but non-isothermal flux tube is considered and a local cutoff frequency is derived. The effects of different temperature profiles on this local cutoff frequency are studied by considering different power-law temperature distributions as well as the semi-empirical VAL C model of the solar atmosphere. The results show that the conditions for wave propagation strongly depend on the temperature gradients. Moreover, the local cutoff frequency calculated for the VAL C model gives constraints on the range of wave frequencies that are propagating in different parts of the solar atmosphere. These theoretically predicted constraints are compared to observational data and are used to discuss the role played by transverse tube waves in the atmospheric heating and dynamics, and in the excitation of solar atmospheric oscillations.Comment: To be publishd in ApJ Vol. 763. 10 pages, 3 Postscript figure
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