M. Turlakov, Phys. Rev. Lett., 93, 035501, (2004).
^
Phenomenologically assuming a sharp decrease of shear relaxation time for large wavevector k > kξ
density modes (where kξ is of order of inverse of several interatomic distances a), I develop a general
only $\omega^4$ density of states for oscillators with disorder
New experimental and theoretical observations have questioned the origin of the boson peak and the linear in T specific heat exclusively from disorder and TLS.
The linear in T behavior in the specific heat is stronger as the modes are more localized and crosses over to a $T^3$ (Debye) regime at a temperature $T^\star \sim \sqrt{ v^3/D}$, where v is the speed of sound.
In summary, we have shown that the same physical mechanism is fundamental for such seemingly different phenomena as the formation of the two-level systems in glasses and the boson peak in the reduced density of low-frequency
vibrational states. In this way, **two of the most fundamental properties of glasses are interconnected
In our theory, it follows naturally. The physical reason for the small value of the parameter C is that only a small fraction of all created TLS’s can actually tunnel in realistic time scales.
## Turlakov 2004 [Universal sound absorption in low-temperature glasses](https://knowen-production.s3.amazonaws.com/uploads/attachment/file/4465/Low-temperature%2Bglasses%2BTurlakov%2B2003.pdf)
M. Turlakov, Phys. Rev. Lett., 93, 035501, (2004).
^
> Phenomenologically assuming a sharp decrease of shear relaxation time for large wavevector k > kξ
> density modes (where kξ is of order of inverse of several interatomic distances a), I develop a general
## only $\omega^4$ density of states for oscillators with disorder
2022 [Vibrational phenomena in glasses at low temperatures captured by field theory of disordered harmonic oscillators](https://arxiv.org/pdf/2211.10891.pdf)
no dipole interaction
## 2020 [A new paradigm for the low-T glassy-like thermal properties of solids](https://arxiv.org/pdf/2008.01407.pdf)
> **New experimental and theoretical observations have questioned the origin of the boson peak and the linear in T specific heat exclusively from disorder and TLS.**
- [Hydrodynamics of disordered marginally stable matter](https://journals.aps.org/prresearch/pdf/10.1103/PhysRevResearch.1.012010)
> The linear in T behavior in the specific heat is stronger as the modes are more localized and crosses over to a $T^3$ (Debye) regime at a temperature $T^\star \sim \sqrt{ v^3/D}$, where v is the speed of sound.
## 2007 [Vibrational instability, two-level systems, and the boson peak in glasses](https://core.ac.uk/download/pdf/34939243.pdf)
D. A. Parshin
> In summary, we have shown that **the same physical mechanism is fundamental for such seemingly different phenomena** as the formation of the two-level systems in glasses and the boson peak in the reduced density of low-frequency
> vibrational states. In this way, **two of the most fundamental properties of glasses are interconnected
> In our theory, it follows naturally. The physical reason for the small value of the parameter C is that only a small fraction of all created TLS’s can actually tunnel in realistic time scales.
- https://arxiv.org/pdf/0711.0461.pdf
https://arxiv.org/pdf/cond-mat/0203165.pdf
- 2022 [Boson-peak vibrational modes in glasses feature hybridized phononic and quasilocalized excitations](https://arxiv.org/pdf/2210.10326.pdf)
