2020-06-08

UTAPwiki/セミナー/初期宇宙・相対論速報

Cosmological superfluids and phonons †

Kohei Kamada †

Spontaneous space-time symmetry breaking is now known to be a key to explore cosmology
such as inflation, dark energy, and dark matter.
In this talk, I will introduce the way to understand the cosmological perturbation
as the Nambu-Goldstone mode of the space-time symmetry breaking
and to construct their effective field theory, following the references [1,2].
I start from the brief introduction of the coset construction and inverse Higgs constraints,
Then I discuss the way to understand the perturbation to be the phonons in superfluids,
which is related to e.g., DBI and cuscuton
and construct their effective Lagrangian.
If time allows, I will also discuss the appearance of other (unconventional) types of phonons.

References
[1] Enrico Pajer, David Stefanyszyn, "Symmetric Superfluids", arXiv:1812.05133
[2] Tanguy Grall, Sadra Jazayeri, David Stefanyszyn, "The Cosmological Phonon: Symmetries and Amplitudes on Sub-Horizon Scales”, arXiv:2005.12937
[3] Sidney R. Coleman, J. Wess, Bruno Zumino, “Structure of phenomenological Lagrangians. 1“, Phys.Rev. 177 (1969) 2239-2247
[4] Curtis G. Jr. Callan, Sidney R. Coleman, J. Wess, Bruno Zumino, “Structure of phenomenological Lagrangians. 1“, Phys.Rev. 177 (1969) 2247-2250
[5] E.A. Ivanov, V.I. Ogievetsky, "The Inverse Higgs Phenomenon in Nonlinear Realizations”, Teor.Mat.Fiz. 25 (1975) 164-177,
[6] D.T. Son, “Low-energy quantum effective action for relativistic superfluids”, hep-ph/0204199