Particles with Internal Degrees of Freedom
Abstract
A development of a structurally complex particle concept to the case of general interaction potentials between its components is proposed. A structurally complex particle is defined by the restricted problem of N+1 bodies of different masses, which is reduced to the N body problem. Based on the Lagrangian description, a Hamiltonian formalism is formulated and the resulting first integrals of motion are discussed. The absence of equipartition among the degrees of freedom is demonstrated. Using the virial theorem, it is
proved that the energy of internal degrees of freedom does not exceed a certain fraction of the initial energy, depending on the ratio of the masses of internal particles to the mass of the shell. An exactly integrable case of a one-dimensional particle with two internal degrees of freedom is considered. The oscillation frequencies of such a structurally complex particle are determined by their masses and the mass of the shell. The energy distribution over them is not uniform. Universal relations are obtained for the distribution of the kinetic and potential energies of internal particles, which are independent of the choice of initial conditions. These relations provide
more detailed information about the energy distribution than the virial relations.
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References
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Copyright (c) 2026 Kostyantyn M. Kulyk, Maryna A. Ratner, Volodymyr V. Yanovsky

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