English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We compute cosmological perturbations for a generic self-gravitating mediadescribed by four derivatively- coupled scalar fields. Depending on theinternal symmetries of the action for the scalar fields, one can describeperfect fluids, superfluids, solids and supersolids media. Symmetries dictateboth dynamical and thermodynamical properties of the media. Generically, scalarperturbations include, besides the gravitational potential, an additionalnon-adiabatic mode associated with the entropy per particle {\sigma}. Whileperfect fluids and solids are adiabatic with {\sigma} constant in time,superfluids and supersolids feature a non-trivial dynamics for {\sigma}.Special classes of isentropic media with zero {\sigma} can also be found.Tensor modes become massive for solids and supersolids. Such an effectiveapproach can be used to give a very general and symmetry driven modelling ofthe dark sector.

Fluids, Superfluids and Supersolids: Dynamics and Cosmology of Self Gravitating Media