Theoretical seminar. Toftul


9 Lomonosov st.

room 2530


Ivan Toftul

'Linear Acoustics: Base Equations, Mie Scattering, Forces and Torques. Optics approach (educational seminar)'

Abstract: Linear acoustics theory is an old but still very attractive field of research due to its simplicity and close relation with the everyday human experience.  Being heavily studied in the past, main achievements can be reformulated in the language of modern optics and nanophotonics for the sake of simplification.  In this educational seminar, at first, we go through the fundamentals of linear harmonic waves in acoustic theory including 1st order Navier-Stokes equation and equation of continuity.  Afterwards, we touch on the media description topic.  Then, we briefly solve the scalar Mie scattering problem and introduce the concept of polarizabilities in acoustics.  Finally, we describe the canonical momentum of the acoustic waves and its connection with force and torque in Rayleigh limit.  Almost everything is going to be done in parallel with the standard electromagnetic theory which we all got used to. Last topics are based on the personal contribution (Phys. Rev. Lett. 123, 183901).