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 investigate the effect of inhomogeneity on primordial black hole formationin the matter dominated era. In the gravitational collapse of an inhomogeneousdensity distribution, a black hole forms if apparent horizon preventsinformation of the central region of the configuration from leaking. Sinceinformation cannot propagate faster than the speed of light, we identify thethreshold of the black hole formation by considering the finite speed forpropagation of information. We show that the production probability$\beta_{inhom}(\sigma)$ of primordial black holes, where $\sigma$ is densityfluctuation at horizon entry, is significantly enhanced from that derived inprevious work in which the speed of propagation was effectively regarded asinfinite. For $\sigma \ll 1$, we obtain $\beta_{inhom}\simeq 3.70\sigma^{3/2}$, which is larger by about an order of magnitude than theprobability derived in earlier work by assuming instantaneous propagation ofinformation.

Effect of Inhomogeneity on Primordial Black Hole Formation in the Matter Dominated Era