D. A. Parshin

Anharmonicity, vibrational instability, and the Boson peak in glasses

We show that a vibrational instability of the spectrum of weakly interacting quasilocal harmonic modes creates the maximum in the inelastic scattering intensity in glasses, the Boson peak. The instability, limited by anharmonicity, causes a complete reconstruction of the vibrational density of states (DOS) below some frequency

Pressure dependence of the boson peak in glasses

{\ensuremath{\omega}}_{c},

Interaction of Soft Modes and Sound Waves in Glasses

proportional to the strength of interaction. The DOS of the new harmonic modes is independent of the actual value of the anharmonicity. It is a universal function of frequency depending on a single parameter \char22{} the Boson peak frequency

Theory of low-energy Raman scattering in glasses.

{\ensuremath{\omega}}_{b}

Heat release in glasses at low temperatures

which is a function of interaction strength. The excess of the DOS over the Debye value is

Theory of low-temperature thermal expansion of glasses.

\ensuremath{\propto}{\ensuremath{\omega}}^{4}

Nonlinear resonant attenuation in glasses and spectral diffusion.

at low frequencies and linear in

Non-Ohmic Microwave Hopping Conductivity

\ensuremath{\omega}

Nonlinear relaxational ultrasonic absorption in metallic glasses

in the interval

Spectral diffusion in glasses at low temperatures. The ``burned-out hole'' phenomenon and nonlinear resonant microwave and sound absorption

{\ensuremath{\omega}}_{b}\ensuremath{\ll}\ensuremath{\omega}\ensuremath{\ll}{\ensuremath{\omega}}_{c}.