Jack Tremarco
Nov19-04, 11:33 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>I have another basic question about string theory. If I have N\ncoincident D-branes, it is well known that the quantum field theory\nthat lives on the world volume of these branes is some YM-theory. My\nquestion is about the gauge group: I have heard the statement that one\ncan get a group like U(N) if the center of mass (of the brane stack)\nis considered not fixed or a special group (det=1, i.e. something like\nSU(N)) if the center of mass is fixed. Is this true? Can someone\nconvince me of it an explain? Why does the determinant have to be one\nif the COM is fixed?\n\nThanks in advance, and thanks also for the excellent answers I got\nhere in the past.\n\nBest,\nJack\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>I have another basic question about string theory. If I have N
coincident D-branes, it is well known that the quantum field theory
that lives on the world volume of these branes is some YM-theory. My
question is about the gauge group: I have heard the statement that one
can get a group like U(N) if the center of mass (of the brane stack)
is considered not fixed or a special group (det=1, i.e. something like
SU(N)) if the center of mass is fixed. Is this true? Can someone
convince me of it an explain? Why does the determinant have to be one
if the COM is fixed?
Thanks in advance, and thanks also for the excellent answers I got
here in the past.
Best,
Jack
coincident D-branes, it is well known that the quantum field theory
that lives on the world volume of these branes is some YM-theory. My
question is about the gauge group: I have heard the statement that one
can get a group like U(N) if the center of mass (of the brane stack)
is considered not fixed or a special group (det=1, i.e. something like
SU(N)) if the center of mass is fixed. Is this true? Can someone
convince me of it an explain? Why does the determinant have to be one
if the COM is fixed?
Thanks in advance, and thanks also for the excellent answers I got
here in the past.
Best,
Jack