Comment on ‘Acoustic axes in weak triclinic anisotropy’ by Václav Vavryčuk

Acoustic axes in elasticity

New results are presented for the degeneracy condition of elastic waves in anisotropic materials. The condition for the existence of acoustic axes involves a traceless symmetric third order tensor that must vanish identically. It is shown that all previous representations of the degeneracy condition follow from this acoustic axis tensor. The conditions for existence of acoustic axes in elastic ...

Comment on “ Anomalously Large Gap Anisotropy in

Comment on "Irrelevant variables, Landau expansions, and cubic anisotropy."

The relationship of the XY model, which arises from a C4 " image, to the phase transition in the rare-earth molybdate Tb2(Mo04)3 (TMO) is discussed. We point out that this model does not describe the TMO transition, but that a Landau expansion arising from a C4 image is the appropriate free-energy model. Recently, Galam' considered phase transitions occurring in the XY model with cubic anisotro...

The psychophysics of order and anisotropy: Comment on Riemer.

Riemer’s paper discusses a neglected yet important topic in the psychological literature: the consequences for psychology (and psychophysics) from the ‘anisotropy’ of time. The paper presents an argument that there are unique kinds of challenges for psychophysics from such temporal anisotropy: (a) Challenges because the psychological experience of time has temporal anisotropy and the physical c...

Influence of Strong Acoustic Anisotropy on Reflection of Bulk Acoustic Waves in Crystals

Propagation and reflection of plane elastic waves in the acousto-optic crystals tellurium dioxide and calomel as well as in the ferroelectric material barium titanate is examined in the paper. The reflection of the waves from a free and flat boundary separating the crystal and the vacuum is investigated in the (001) planes of TeO2, Hg2Cl2, and BaTiO3 in the case of glancing acoustic incidence o...