Thermal hydrodynamic fluctuations of polymer globules

Thermal excitations of polymer globules have been studied within the hydrodynamic correlation theory. The globule consists of the elastic and fluid components and is immersed into another fluid. Both fluids are considered to be compressible and Newtonian. The interaction between polymer and fluid components of the globule is described by an effective local friction force proportional to the difference between component velocities. The fluctuation inside the globule described by the linearized equations of Navier-Stokes and elasticity theory coupled by Darcyʹs law. In the case of perfect coupling at the interface the spectral densities of fluctuations are obtained using the fluctuation-dissipation theorem. The hydrodynamic correlation functions and the dynamical structure factor are found.