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Johan Hansson & Fredrik Sandin, Luleå tekniska universitet
Artikel om våra "preonstjärnor" i New Scientist ("The World's No.1 Science & Technology
Magazine") 6 November 2004, sid.19
http://www.newscientist.com/contents/issue/2472.html
"Micro-stars may manage to avoid black-hole
fate"
New Scientist vol 184 issue 2472 - 06 November 2004, page 19
COULD the universe be filled with strange stars the size of footballs? Perhaps,
if the big bang fireball churned out superdense stars just a few tens of
centimetres wide. And contrary to conventional theory, such stars might even
form today when ordinary stars explode.
When a massive star runs out of fuel at the end of its life, it collapses and
explodes. If a core about 2 or 3 times as massive as the sun remains, it forms
a neutron star, a superdense ball of nuclear matter typically 10 kilometres
wide. And if the core is heavier, it should collapse into a black hole.
But now Johan Hansson and Fredrik Sandin of Luleå University of
Technology in Sweden have suggested a third possibility, based on the
properties of hypothetical particles called preons. Some theorists believe
preons could be the building blocks of elementary particles such as quarks and
electrons. Preons, they say, could halt the collapse into a black hole and end
up forming a football-sized preon star.
Their calculations suggest a preon star would form when matter reached a
density of about 1017 tonnes per cubic centimetre. This makes preon balls
even more likely to have formed in dense regions of the big bang fireball than
in collapsing stars. To be stable, a preon star would have to have a radius of
between roughly a tenth of a millimetre and a metre, and a mass up to 100
times that of the Earth (www.arxiv.org/abs/astro-ph/0410417).
However, these stars might not emit much light, which could explain why they
have not been spotted, they say.
Preon stars would be somewhere around the size of a football, with a mass up
to 100 times that of the Earth
Rabindra Mohapatra, a physicist at the University of Maryland in College Park,
says that preon models are not wildly popular today because they do not
explain the properties of elementary particles neatly enough. "Preon models
have gone out of fashion, but there is nothing in the domain of experiments
that contradicts the idea."
Hazel Muir
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Originalartiklar:
http://xxx.lanl.gov/abs/astro-ph/0410417
http://xxx.lanl.gov/abs/astro-ph/0410407
http://xxx.lanl.gov/abs/hep-ph/0208135