E-viri
Odprti dostop
-
Adams, Fred C; Howe, Alex R; Grohs, Evan; Fuller, George M
arXiv.org, 03/2021Paper, Journal Article
Deuterium represents the only bound isotope in the universe with atomic mass number \(A=2\). Motivated by the possibility of other universes, where the strong force could be stronger, this paper considers the effects of bound diprotons and dineutrons on stars. We find that the existence of additional stable nuclei with \(A=2\) has relatively modest effects on the universe. Previous work indicates that Big Bang Nucleosynthesis (BBN) produces more deuterium, but does not lead to catastrophic heavy element production. This paper revisits BBN considerations and confirms that the universe is left with an ample supply of hydrogen and other light nuclei for typical cosmological parameters. Using the \(MESA\) numerical package, we carry out stellar evolution calculations for universes with stable diprotons, with nuclear cross sections enhanced by large factors \(X\). This work focuses on \(X=10^{15}-10^{18}\), but explores the wider range \(X\) = \(10^{-3}-10^{18}\). For a given stellar mass, the presence of stable diprotons leads to somewhat brighter stars, with the radii and photospheric temperatures roughly comparable to thoese of red giants. The central temperature decreases from the characteristic value of \(T_c\approx1.5\times10^7\) K for hydrogen burning down to the value of \(T_c\approx10^6\) K characteristic of deuterium burning. The stellar lifetimes are smaller for a given mass, but with the extended possible mass range, the smallest stars live for trillions of years, far longer than the current cosmic age. Finally, the enhanced cross sections allow for small, partially degenerate objects with mass \(M_\ast=1-10M_J\) to produce significant steady-state luminosity and thereby function as stars.
![loading ... loading ...](themes/default/img/ajax-loading.gif)
Vnos na polico
Trajna povezava
- URL:
Faktor vpliva
Dostop do baze podatkov JCR je dovoljen samo uporabnikom iz Slovenije. Vaš trenutni IP-naslov ni na seznamu dovoljenih za dostop, zato je potrebna avtentikacija z ustreznim računom AAI.
Leto | Faktor vpliva | Izdaja | Kategorija | Razvrstitev | ||||
---|---|---|---|---|---|---|---|---|
JCR | SNIP | JCR | SNIP | JCR | SNIP | JCR | SNIP |
Baze podatkov, v katerih je revija indeksirana
Ime baze podatkov | Področje | Leto |
---|
Povezave do osebnih bibliografij avtorjev | Povezave do podatkov o raziskovalcih v sistemu SICRIS |
---|
Vir: Osebne bibliografije
in: SICRIS
To gradivo vam je dostopno v celotnem besedilu. Če kljub temu želite naročiti gradivo, kliknite gumb Nadaljuj.