View Full Version : LIGO may prove string theory
Neutron
Jun17-04, 04:20 PM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>[Original subject: Newly devised test may confirm strings as fundamental\nconstituent of matter, energy ... Moderator\'s note, LM]\n\nExperimental verification would mean more spatial dimensions exist\n\nAccording to string theory, all the different particles that\nconstitute physical reality are made of the same thing--tiny looped\nstrings whose different vibrations give rise to the different\nfundamental particles that make up everything we know. Whether this\ntheory correctly portrays fundamental reality is one of the biggest\nquestions facing physicists.\n\nIn the June on-line Journal of High Energy Physics (JHEP), three\ntheoretical physicists propose the most viable test to date for\ndetermining whether string theory is on the right track. The effect\nthat they describe and that could be discovered by LIGO (Laser\nInterferometer Gravitational-Wave Observatory), a facility for\ndetecting gravitational waves that is just becoming operational, could\nprovide support for string theory within two years.\n\nFull story: http://www.physorg.com/news199.html\n\n[Moderator\'s note: see also the papers below... LM]\n\nhttp://arxiv.org/abs/hep-th/0405229\nhttp://arxiv.org/abs/hep-th/0312067\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>[Original subject: Newly devised test may confirm strings as fundamental
constituent of matter, energy ... Moderator's note, LM]
Experimental verification would mean more spatial dimensions exist
According to string theory, all the different particles that
constitute physical reality are made of the same thing--tiny looped
strings whose different vibrations give rise to the different
fundamental particles that make up everything we know. Whether this
theory correctly portrays fundamental reality is one of the biggest
questions facing physicists.
In the June on-line Journal of High Energy Physics (JHEP), three
theoretical physicists propose the most viable test to date for
determining whether string theory is on the right track. The effect
that they describe and that could be discovered by LIGO (Laser
Interferometer Gravitational-Wave Observatory), a facility for
detecting gravitational waves that is just becoming operational, could
provide support for string theory within two years.
Full story: http://www.physorg.com/news199.html
[Moderator's note: see also the papers below... LM]
http://arxiv.org/abs/http://www.arxiv.org/abs/hep-th/0405229
http://arxiv.org/abs/http://www.arxiv.org/abs/hep-th/0312067
Urs Schreiber
Jun18-04, 05:00 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>"Neutron" <neutron_p@lycos.com> schrieb im Newsbeitrag\nnews:602d73d9.0406171255.66373ed6-100000@posting.google.com...\n\n> [Moderator\'s note: see also the papers below... LM]\n>\n> http://arxiv.org/abs/hep-th/0405229\n> http://arxiv.org/abs/hep-th/0312067\n\n\nI had seen the original paper "Cosmic F- and D-strings" and didn\'t quite\nunderstand at that time the crucial idea\n(http://golem.ph.utexas.edu/string/archives/000271.html) . In fact, after\nre-reading that entry I still feel that my problems in understanding this\nidea are well summarized by Robert Helling\'s remark at\nhttp://golem.ph.utexas.edu/string/archives/000271.html#c000342 .\n\nFor instance: What keeps these enormous(=highly excited)\nfundamental/D-strings from collapsing under their own gravity, as computed\nfor instance in hep-th/9907030?\n\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>"Neutron" <neutron_p@lycos.com> schrieb im Newsbeitrag
news:602d73d9.0406171255.66373ed6-100000@posting.google.com...
> [Moderator's note: see also the papers below... LM]
>
> http://arxiv.org/abs/http://www.arxiv.org/abs/hep-th/0405229
> http://arxiv.org/abs/http://www.arxiv.org/abs/hep-th/0312067
I had seen the original paper "Cosmic F- and D-strings" and didn't quite
understand at that time the crucial idea
(http://golem.ph.utexas.edu/string/archives/000271.html) . In fact, after
re-reading that entry I still feel that my problems in understanding this
idea are well summarized by Robert Helling's remark at
http://golem.ph.utexas.edu/string/archives/000271.html#c000342 .
For instance: What keeps these enormous(=highly excited)
fundamental/D-strings from collapsing under their own gravity, as computed
for instance in http://www.arxiv.org/abs/hep-th/9907030?
Lubos Motl
Jun19-04, 07:30 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>On Fri, 18 Jun 2004, Urs Schreiber wrote:\n\n> For instance: What keeps these enormous(=highly excited)\n> fundamental/D-strings from collapsing under their own gravity, as computed\n> for instance in hep-th/9907030?\n\nI don\'t think that it is such a good idea to think about the macroscopic\nstrings as "highly excited microscopic strings". Using oscillators and\ntheir action on the grond state is a great technology to understand a\ncouple of low-lying excitations, but not necessarily the macroscopic\nclassical limit of large strings.\n\nBut Polchinski et al. want to consider strings of astronomical sizes,\nstretched between the points on the cosmic horizon, and being almost\nexactly straight. A completely straight charged string is BPS, and it is\ncompletely stable. In fact, it has no priviliged direction where it should\nstart to collapse. If it\'s wiggly a bit, you can still use the\napproximation of a classical (macroscopic) string.\n\nA non-supersymmetric black string would have Gregory-Laflamme-like\ninstabilities, but I think that this is not what they consider.\nThe stringy cosmic strings should be distinguishable by different\nprobabilities of interaction than some other strings - the probability of\ntwo F-strings interact probably goes like g^2, and so on.\n_____________________________________________ _________________________________\nE-mail: lumo@matfyz.cz fax: +1-617/496-0110 Web: http://lumo.matfyz.cz/\neFax: +1-801/454-1858 work: +1-617/496-8199 home: +1-617/868-4487 (call)\n^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>On Fri, 18 Jun 2004, Urs Schreiber wrote:
> For instance: What keeps these enormous(=highly excited)
> fundamental/D-strings from collapsing under their own gravity, as computed
> for instance in http://www.arxiv.org/abs/hep-th/9907030?
I don't think that it is such a good idea to think about the macroscopic
strings as "highly excited microscopic strings". Using oscillators and
their action on the grond state is a great technology to understand a
couple of low-lying excitations, but not necessarily the macroscopic
classical limit of large strings.
But Polchinski et al. want to consider strings of astronomical sizes,
stretched between the points on the cosmic horizon, and being almost
exactly straight. A completely straight charged string is BPS, and it is
completely stable. In fact, it has no priviliged direction where it should
start to collapse. If it's wiggly a bit, you can still use the
approximation of a classical (macroscopic) string.
A non-supersymmetric black string would have Gregory-Laflamme-like
instabilities, but I think that this is not what they consider.
The stringy cosmic strings should be distinguishable by different
probabilities of interaction than some other strings - the probability of
two F-strings interact probably goes like g^2, and so on.
__{_______________________________________________ _____________________________}
E-mail: lumo@matfyz.cz fax: +1-617/496-0110 Web: http://lumo.matfyz.cz/
eFax: +1-801/454-1858 work: +1-617/496-8199 home: +1-617/868-4487 (call)
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