Reentrant violation of special relativity in the low-energy corner
G. E. Volovik
Low Temperature Laboratory, Helsinki University of Technology
FIN-02015 HUT, Finland
L. D. Landau Institute for Theoretical Physics, 117334 Moscow, Russia
PACS: 11.30.-j, 14.60.Pq, 67.57.-z
Abstract
In the effective relativistic quantum field theories the energy
region, where the special relativity holds, can be sandwiched from both the
high and low energies sides by domains where the special relativity is
violated. An example is provided by 3He-A where the relativistic quantum
field theory emerges as the effective theory. The reentrant violation of the
special relativity in the ultralow energy corner is accompanied by the
redistribution of the momentum-space topological charges between the
fermionic flavors. At this ultralow energy an exotic massless fermion with
the topological charge N3=2 arises, whose energy spectrum mixes the
classical and relativistic behavior. This effect can lead to neutrino
oscillations if neutrino flavors are still massless at this energy scale.