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 Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

The aim of the present work is to better understand the gravitational dragforces, i.e. dynamical friction, acting on massive objects moving through aself-interacting Bose-Einstein condensate, also known as a superfluid, atfinite temperatures. This is relevant for light scalar models of dark matterwith weak self-interactions that require nonzero temperatures, or that havebeen heated inside galaxies. We derived expressions for dynamical frictionusing linear perturbation theory, and compared these to numerical simulationsin which nonlinear effects are included. After testing the linear result, itwas applied to the Fornax dwarf spheroidal galaxy, and two of itsgravitationally bound globular clusters. Dwarf spheroidals are well-suited forindirectly probing properties of dark matter, and so by estimating the rate atwhich these globular clusters are expected to sink into their host halo due todynamical friction, we inferred limits on the superfluid dark matter parameterspace. The dynamical friction in a finite-temperature superfluid is found tobehave very similarly to the zero-temperature limit, even when the thermalcontributions are large. However, when a critical velocity for the superfluidflow is included, the friction force can transition from the zero-temperaturevalue to the value in a conventional fluid. Increasing the mass of theperturbing object induces a similar transition to when lowering the criticalvelocity. When applied to two of Fornax's globular clusters, we find that theparameter space preferred in the literature for a zero-temperature superfluidyields decay times that are in agreement with observations. However, thepresent work suggests that increasing the temperature, which is expected tochange the preferred parameter space, may lead to very small decay times, andtherefore pose a problem for finite-temperature superfluid models of darkmatter.

Dynamical friction in Bose-Einstein condensed self-interacting dark matter at finite temperatures, and the Fornax dwarf spheroidal