View Full Version : Question for Lubos.
<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>\n\n\n\nLubos,\n\nI was looking at your paper with Neitzke, hep-th/0301173. I am\nreading 2.4 in the paper and have probably a very basic question. You\nsay it is convenient to choose the branch such that n=0. Other than\nconvenience, is there some basic reason why this branch is preferred\nover any other branch?\n\nThanks,\nScott\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>Lubos,
I was looking at your paper with Neitzke, http://www.arxiv.org/abs/hep-th/0301173. I am
reading 2.4 in the paper and have probably a very basic question. You
say it is convenient to choose the branch such that n=0. Other than
convenience, is there some basic reason why this branch is preferred
over any other branch?
Thanks,
Scott
Lubos Motl
Oct25-04, 10:42 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>\nOn Mon, 25 Oct 2004, Scott wrote:\n\n> I was looking at your paper with Neitzke, hep-th/0301173. I am\n> reading 2.4 in the paper and have probably a very basic question. You\n> say it is convenient to choose the branch such that n=0. Other than\n> convenience, is there some basic reason why this branch is preferred\n> over any other branch?\n\nDear Scott, if I understand your question well, you ask why did we choose\nthe point r=0, close to our contour, to be mapped to z=0 in the tortoise\ncoordinate plane.\n\nIt\'s because the number 0 is easy to work with. You can also choose r=0 to\nbe mapped to z=2.pi.i.n, and the whole argument will be essentially\nunchanged. The choice n=0 is not preferred because of any fundamental\nreason - it is just a matter of convenience. If you choose a different n,\nthe only change that you will have to do is to write (z-2.pi.i.n) instead\nof z everywhere in the rest of the argument - it is as simple as this\nadditive shift.\n\nThe logarithms in the tortoise coordinate fortunately always appear with a\nconstant coefficient only - so the convention about the branch is always a\nmatter of an additive shift, even for more complicated black holes.\n\nDoes it answer your question? If I wrote something incorrectly, I believe\nthat Andy Neitzke will correct me.\n\nAll the best,\nLubos\n____________________________________ __________________________________________\nE-mail: lumo@matfyz.cz fax: +1-617/496-0110 Web: http://lumo.matfyz.cz/\neFax: +1-801/454-1858 work: +1-617/384-9488 home: +1-617/868-4487 (call)\nWebs: http://schwinger.harvard.edu/~motl/ http://motls.blogspot.com/\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 Mon, 25 Oct 2004, Scott wrote:
> I was looking at your paper with Neitzke, http://www.arxiv.org/abs/hep-th/0301173. I am
> reading 2.4 in the paper and have probably a very basic question. You
> say it is convenient to choose the branch such that n=0. Other than
> convenience, is there some basic reason why this branch is preferred
> over any other branch?
Dear Scott, if I understand your question well, you ask why did we choose
the point r=0, close to our contour, to be mapped to z=0 in the tortoise
coordinate plane.
It's because the number is easy to work with. You can also choose r=0 to
be mapped to z=2.\pi.i.n, and the whole argument will be essentially
unchanged. The choice n=0 is not preferred because of any fundamental
reason - it is just a matter of convenience. If you choose a different n,
the only change that you will have to do is to write (z-2.\pi.i.n) instead
of z everywhere in the rest of the argument - it is as simple as this
additive shift.
The logarithms in the tortoise coordinate fortunately always appear with a
constant coefficient only - so the convention about the branch is always a
matter of an additive shift, even for more complicated black holes.
Does it answer your question? If I wrote something incorrectly, I believe
that Andy Neitzke will correct me.
All the best,
Lubos
__{_______________________________________________ _____________________________}
E-mail: lumo@matfyz.cz fax: +1-617/496-0110 Web: http://lumo.matfyz.cz/
eFax: +1-801/454-1858 work: +1-617/384-9488 home: +1-617/868-4487 (call)
Webs: http://schwinger.harvard.edu/~motl/ http://motls.blogspot.com/
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
<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>\n\n\n\nLubos,\nThanks for the reply. I guess a better way to ask the question is\nthis. You had to choose a particular branch. Will your final value\nfor the quasinormal frequency depend on the branch you chose? My\nguess is it doesn\'t, but I aven\'t done any calculations.\n\nThanks,\nScott\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>Lubos,
Thanks for the reply. I guess a better way to ask the question is
this. You had to choose a particular branch. Will your final value
for the quasinormal frequency depend on the branch you chose? My
guess is it doesn't, but I aven't done any calculations.
Thanks,
Scott
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