Friday, March 14, 2025 11:00 MLIT Room 310, Online seminar via MTS Link Barashenkov I.V.Variational formalism for oscillons and breathers Seminar of the scientific department of computational physics Abstract: Oscillons are long-lived localised pulsating states in the nonlinear Klein-Gordon equations. We formulate a multiscale variational method for the analysis of oscillons that is free from singularities that marred all previously proposed variational techniques. For the model with a symmetric vacuum, a single-harmonic variational Ansatz provides an excellent agreement with the numerical results. For a model with broken symmetry (the φ4 equation), the numerical analysis reveals that the energy-frequency diagram of the standing wave is fragmented into disjoint segments with frequencies ωn+1<ω<ωn. In the interval (ωn+1, ωn), the wave develops small-amplitude wings consisting of the n-th harmonic radiation (n=2,3,...). The variational approximation involving the first, zeroth and second harmonic components provides an accurate description of the oscillon with the frequency in (ω3, ω2), but breaks down as ω falls out of that interval. Information on the seminar and the link to connect are available at Indico. Сonnecting to MTS Link.
