NS5 and Little String Theory [Archive]

Urs Schreiber

Jul20-04, 11:44 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>\nI am trying to get some rough understanding of some aspects of Little\nString Theory. Currently I am looking at Kutasov\'s lecture notes\n"Introduction to Little String Theory".\n\nIn particular, I have nonabelian B-fields in mind and want to understand\nwhat these could have to do with such setups.\n\nSo consider a stack of N NS5 branes. In type IIA, we have D2 branes\nstretched between these NS5s.\n\nThe boundary of the D2s attached to the 5-branes gives us closed strings\nthat are restricted to sit on the NS branes. When the 5-branes coincide\nthe tension of these D2-boundary strings apparently vanishes and their\neffective field theory on the 5-brane is a (2,0) superconformal one.\n\nApparently in type IIB these closed strings sitting on the NS branes arise\nas instanton solution of the low energy gauge theory.\n\n\nHere is a question: Assuming that, what seems to be the case, LST, at\nleast in IIA, can be understood as a theory of closed strings which are\nboundaries of D2 branes, then these closed strings should carry something\nlike a Chan-Paton factor, i.e. they should carry a degree of freedom\nsaying on which one of the N NS barnes they are attached, right?\n\nThis appears to be potentially helpful if one wants to find string states\nthat correspond to a nonabelian 2-form. Somehow closed strings together\nwith CP factors have to enter the game. On the other hand, there would only\nbe a single such CP factor associated with such a closed string, the other\nwould be associated with the other boundary of the corresponding D2.\n\nAre there also any open strings in LST? How do they arise from the full\nstring theory point of view?\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 am trying to get some rough understanding of some aspects of Little
String Theory. Currently I am looking at Kutasov's lecture notes
"Introduction to Little String Theory".

In particular, I have nonabelian B-fields in mind and want to understand
what these could have to do with such setups.

So consider a stack of N NS5 branes. In type IIA, we have D2 branes
stretched between these NS5s.

The boundary of the D2s attached to the 5-branes gives us closed strings
that are restricted to sit on the NS branes. When the 5-branes coincide
the tension of these D2-boundary strings apparently vanishes and their
effective field theory on the 5-brane is a (2,0) superconformal one.

Apparently in type IIB these closed strings sitting on the NS branes arise
as instanton solution of the low energy gauge theory.

Here is a question: Assuming that, what seems to be the case, LST, at
least in IIA, can be understood as a theory of closed strings which are
boundaries of D2 branes, then these closed strings should carry something
like a Chan-Paton factor, i.e. they should carry a degree of freedom
saying on which one of the N NS barnes they are attached, right?

This appears to be potentially helpful if one wants to find string states
that correspond to a nonabelian 2-form. Somehow closed strings together
with CP factors have to enter the game. On the other hand, there would only
be a single such CP factor associated with such a closed string, the other
would be associated with the other boundary of the corresponding D2.

Are there also any open strings in LST? How do they arise from the full
string theory point of view?

Lubos Motl

Jul20-04, 11:44 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 Tue, 20 Jul 2004, Urs Schreiber wrote:\n\n> Here is a question: Assuming that, what seems to be the case, LST, at\n> least in IIA, can be understood as a theory of closed strings which are\n> boundaries of D2 branes, ...\n\nSorry, a very stupid question. Is this interpretation of little strings as\nD2-brane boundaries your conjecture or random guess based on the\nnot-too-shocking identity 2-1=1, or something that you\'ve seen in\nliterature? I am very puzzled by such a statement, and I am still\nconvinced that the little strings carry charges of the fundamental strings\n(dissolved in the NS5-brane). Otherwise I have no way to understand\nT-duality that LST is known to inherit from the "big" string theory and\nother things.\n\nOn the other hand, I of course agree that the membranes stretched between\nthe fivebranes (which is possible and inherited from M-theory) do exist in\nthe LST and they are what becomes the "tensionless strings" behind the\n(2,0) SCFT, but they are not the "little string" with tension 1/alpha\'.\nThe tension of the little strings is 1/alpha\' (times a numerical\nconstant), and they have the same charges and tension as the fundamental\nstrings.\n\nBut the relation between these different viewpoints on dynamics is\nnontrivial, and I have no clue how you want to isolate anything about the\nnon-Abelian 2-forms. Do you know that the little string theory is\nnon-local, for example? If you ask something based on your assumption that\nLST is equivalent to an obscure local theory with non-Abelian 2-forms,\nthen you should know that your assumption is incorrect and the question\ntherefore meaningless.\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\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 Tue, 20 Jul 2004, Urs Schreiber wrote:

> Here is a question: Assuming that, what seems to be the case, LST, at
> least in IIA, can be understood as a theory of closed strings which are
> boundaries of D2 branes, ...

Sorry, a very stupid question. Is this interpretation of little strings as
D2-brane boundaries your conjecture or random guess based on the
not-too-shocking identity 2-1=1, or something that you've seen in
literature? I am very puzzled by such a statement, and I am still
convinced that the little strings carry charges of the fundamental strings
(dissolved in the NS5-brane). Otherwise I have no way to understand
T-duality that LST is known to inherit from the "big" string theory and
other things.

On the other hand, I of course agree that the membranes stretched between
the fivebranes (which is possible and inherited from M-theory) do exist in
the LST and they are what becomes the "tensionless strings" behind the
(2,0) SCFT, but they are not the "little string" with tension 1/\alpha'.
The tension of the little strings is 1/\alpha' (times a numerical
constant), and they have the same charges and tension as the fundamental
strings.

But the relation between these different viewpoints on dynamics is
nontrivial, and I have no clue how you want to isolate anything about the
non-Abelian 2-forms. Do you know that the little string theory is
non-local, for example? If you ask something based on your assumption that
LST is equivalent to an obscure local theory with non-Abelian 2-forms,
then you should know that your assumption is incorrect and the question
therefore meaningless.
__{_______________________________________________ _____________________________}
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)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Urs Schreiber

Jul20-04, 01:26 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>On Tue, 20 Jul 2004, Lubos Motl wrote:\n\n> On Tue, 20 Jul 2004, Urs Schreiber wrote:\n>\n> > Here is a question: Assuming that, what seems to be the case, LST, at\n> > least in IIA, can be understood as a theory of closed strings which are\n> > boundaries of D2 branes, ...\n\n> On the other hand, I of course agree that the membranes stretched between\n> the fivebranes (which is possible and inherited from M-theory) do exist in\n> the LST and they are what becomes the "tensionless strings" behind the\n> (2,0) SCFT, but they are not the "little string" with tension 1/alpha\'.\n\n\nAh, so here was my confusion. Thanks for the explanation.\n\n\n> But the relation between these different viewpoints on dynamics is\n> nontrivial, and I have no clue how you want to isolate anything about the\n> non-Abelian 2-forms. Do you know that the little string theory is\n> non-local, for example?\n\n\nNo, I didn\'t! :-)\n\n\n> If you ask something based on your assumption that\n> LST is equivalent to an obscure local theory with non-Abelian 2-forms,\n> then you should know that your assumption is incorrect and the question\n> therefore meaningless.\n\n\nIt is just that some people that I have talked to are thinking about\napproaches that might perhaps give us nonabelian 2-forms from (2,0)\ntheories in 6 dimensions, and I was just making a naive guess how that\ncould be understood heuristically. I\'ll try to learn more about LST and\nask a better question next time.\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 Tue, 20 Jul 2004, Lubos Motl wrote:

> On Tue, 20 Jul 2004, Urs Schreiber wrote:
>
> > Here is a question: Assuming that, what seems to be the case, LST, at
> > least in IIA, can be understood as a theory of closed strings which are
> > boundaries of D2 branes, ...

> On the other hand, I of course agree that the membranes stretched between
> the fivebranes (which is possible and inherited from M-theory) do exist in
> the LST and they are what becomes the "tensionless strings" behind the
> (2,0) SCFT, but they are not the "little string" with tension 1/\alpha'.

Ah, so here was my confusion. Thanks for the explanation.

> But the relation between these different viewpoints on dynamics is
> nontrivial, and I have no clue how you want to isolate anything about the
> non-Abelian 2-forms. Do you know that the little string theory is
> non-local, for example?

No, I didn't! :-)

> If you ask something based on your assumption that
> LST is equivalent to an obscure local theory with non-Abelian 2-forms,
> then you should know that your assumption is incorrect and the question
> therefore meaningless.

It is just that some people that I have talked to are thinking about
approaches that might perhaps give us nonabelian 2-forms from (2,0)
theories in 6 dimensions, and I was just making a naive guess how that
could be understood heuristically. I'll try to learn more about LST and
ask a better question next time.

Moshe Rozali

Jul20-04, 07:29 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>Lubos Motl <motl@feynman.harvard.edu> wrote in message news:<Pine.LNX.4.31.0407201231280.26189-100000@einstein.physics.harvard.edu>...\n> On Tue, 20 Jul 2004, Urs Schreiber wrote:\n>\n> > Here is a question: Assuming that, what seems to be the case, LST, at\n> > least in IIA, can be understood as a theory of closed strings which are\n> > boundaries of D2 branes, ...\n>\n> Sorry, a very stupid question. Is this interpretation of little strings as\n> D2-brane boundaries your conjecture or random guess based on the\n> not-too-shocking identity 2-1=1, or something that you\'ve seen in\n> literature? I am very puzzled by such a statement, and I am still\n> convinced that the little strings carry charges of the fundamental strings\n> (dissolved in the NS5-brane). Otherwise I have no way to understand\n> T-duality that LST is known to inherit from the "big" string theory and\n> other things.\n>\n> On the other hand, I of course agree that the membranes stretched between\n> the fivebranes (which is possible and inherited from M-theory) do exist in\n> the LST and they are what becomes the "tensionless strings" behind the\n> (2,0) SCFT, but they are not the "little string" with tension 1/alpha\'.\n> The tension of the little strings is 1/alpha\' (times a numerical\n> constant), and they have the same charges and tension as the fundamental\n> strings.\n>\n> But the relation between these different viewpoints on dynamics is\n> nontrivial, and I have no clue how you want to isolate anything about the\n> non-Abelian 2-forms. Do you know that the little string theory is\n> non-local, for example? If you ask something based on your assumption that\n> LST is equivalent to an obscure local theory with non-Abelian 2-forms,\n> then you should know that your assumption is incorrect and the question\n> therefore meaningless.\n> __________________________________________________ ____________________________\n> E-mail: lumo@matfyz.cz fax: +1-617/496-0110 Web: http://lumo.matfyz.cz/\n> eFax: +1-801/454-1858 work: +1-617/496-8199 home: +1-617/868-4487 (call)\n> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^\nLubos,\n\nA brief comment- from the 11dim viewpoint the "little strings" are\nmemebranes ending on the fivebranes and wrapping the compact\ntransverse direction (so they do not become tensionless when the\nfivebranes coincide). This is the viewpoint in Berkooz-Rozali-Seiberg\npaper, which goes over to the "strings dissolved in fivebranes"\npicture when reducing to type IIA. In modern language probably both\nsuch mental pictures are more relevant to the holographic dual to LST,\nrather than LST itself, whatever that is.\n\nbest,\n\nMoshe\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>Lubos Motl <motl@feynman.harvard.edu> wrote in message news:<Pine.LNX.4.31.0407201231280.26189-100000@einstein.physics.harvard.edu>...
> On Tue, 20 Jul 2004, Urs Schreiber wrote:
>
> > Here is a question: Assuming that, what seems to be the case, LST, at
> > least in IIA, can be understood as a theory of closed strings which are
> > boundaries of D2 branes, ...
>
> Sorry, a very stupid question. Is this interpretation of little strings as
> D2-brane boundaries your conjecture or random guess based on the
> not-too-shocking identity 2-1=1, or something that you've seen in
> literature? I am very puzzled by such a statement, and I am still
> convinced that the little strings carry charges of the fundamental strings
> (dissolved in the NS5-brane). Otherwise I have no way to understand
> T-duality that LST is known to inherit from the "big" string theory and
> other things.
>
> On the other hand, I of course agree that the membranes stretched between
> the fivebranes (which is possible and inherited from M-theory) do exist in
> the LST and they are what becomes the "tensionless strings" behind the
> (2,0) SCFT, but they are not the "little string" with tension 1/\alpha'.
> The tension of the little strings is 1/\alpha' (times a numerical
> constant), and they have the same charges and tension as the fundamental
> strings.
>
> But the relation between these different viewpoints on dynamics is
> nontrivial, and I have no clue how you want to isolate anything about the
> non-Abelian 2-forms. Do you know that the little string theory is
> non-local, for example? If you ask something based on your assumption that
> LST is equivalent to an obscure local theory with non-Abelian 2-forms,
> then you should know that your assumption is incorrect and the question
> therefore meaningless.
> __{_______________________________________________ _____________________________}
> 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)
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Lubos,

A brief comment- from the 11dim viewpoint the "little strings" are
memebranes ending on the fivebranes and wrapping the compact
transverse direction (so they do not become tensionless when the
fivebranes coincide). This is the viewpoint in Berkooz-Rozali-Seiberg
paper, which goes over to the "strings dissolved in fivebranes"
picture when reducing to type IIA. In modern language probably both
such mental pictures are more relevant to the holographic dual to LST,
rather than LST itself, whatever that is.

best,

Moshe

Lubos Motl

Jul20-04, 11:24 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>On Tue, 20 Jul 2004, Urs Schreiber wrote:\n\n> > non-Abelian 2-forms. Do you know that the little string theory is\n> > non-local, for example?\n>\n> No, I didn\'t! :-)\n\nMaybe you just want to think about the (2,0) SCFT (superconformal field\ntheory)? It is the low energy limit of the type IIA little string theory,\nand it is (as far as we believe) local. It has no 1/alpha\' strings of the\ntype I mentioned before (they are decoupled as very massive in the new\nlimit), but it has your cylindrical membrane-strings which must be\ndescribed by "some" non-Abelian 2-form potentials, whatever it is.\n\nPlease distinguish (2,0) SCFT and LST. The former is a limit of M5-branes\nin M-theory (low energies, coincident M5-branes, no scale), while the\nlatter are limits of NS5-branes in type II string theory and is richer and\nnon-local (and they have a fundamental string scale).\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 Tue, 20 Jul 2004, Urs Schreiber wrote:

> > non-Abelian 2-forms. Do you know that the little string theory is
> > non-local, for example?
>
> No, I didn't! :-)

Maybe you just want to think about the (2,0) SCFT (superconformal field
theory)? It is the low energy limit of the type IIA little string theory,
and it is (as far as we believe) local. It has no 1/\alpha' strings of the
type I mentioned before (they are decoupled as very massive in the new
limit), but it has your cylindrical membrane-strings which must be
described by "some" non-Abelian 2-form potentials, whatever it is.

Please distinguish (2,0) SCFT and LST. The former is a limit of M5-branes
in M-theory (low energies, coincident M5-branes, no scale), while the
latter are limits of NS5-branes in type II string theory and is richer and
non-local (and they have a fundamental string scale).
__{_______________________________________________ _____________________________}
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)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Lubos Motl

Jul21-04, 10:16 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 Tue, 20 Jul 2004, Moshe Rozali wrote:\n\n> A brief comment- from the 11dim viewpoint the "little strings" are\n> memebranes ending on the fivebranes and wrapping the compact\n> transverse direction (so they do not become tensionless when the\n> fivebranes coincide). This is the viewpoint in Berkooz-Rozali-Seiberg\n\nHi Moshe,\n\ngood to see you here again! How can a membrane, giving a string, be\nsimultaneously stretched between fivebranes as well as wrapped on the\ntransverse (11th?) dimension? If you start with a membrane and you want to\nget a string, you must get rid of 1 dimension, and there seem to be 2 ways\nhow to do so: this killed dimension is either the circle - the membrane is\nwrapped on the 11th circular dimension, and this gives you the tension of\nthe fundamental string (which I believe is the scale of the little string\ntheory - the tension of the string) - or it can be a line interval in\nwhich case the membrane is stretched between two fivebranes - in which\ncase you get strings that are tensionless for coincident fivebranes. Or\ncan you eat a cake and have it too?\n\nIs your paper with Nati and Micha the paper where LST was first proposed?\n\nBest\nLubos\n________________________ __________________________________________________ ____\nE-mail: lumo@matfyz.cz fax: +1-617/496-0110 Web: http://lumo.matfyz.cz/\neFax: +1-801/454-1858 work: +1-617/496-8199 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 Tue, 20 Jul 2004, Moshe Rozali wrote:

> A brief comment- from the 11dim viewpoint the "little strings" are
> memebranes ending on the fivebranes and wrapping the compact
> transverse direction (so they do not become tensionless when the
> fivebranes coincide). This is the viewpoint in Berkooz-Rozali-Seiberg

Hi Moshe,

good to see you here again! How can a membrane, giving a string, be
simultaneously stretched between fivebranes as well as wrapped on the
transverse (11th?) dimension? If you start with a membrane and you want to
get a string, you must get rid of 1 dimension, and there seem to be 2 ways
how to do so: this killed dimension is either the circle - the membrane is
wrapped on the 11th circular dimension, and this gives you the tension of
the fundamental string (which I believe is the scale of the little string
theory - the tension of the string) - or it can be a line interval in
which case the membrane is stretched between two fivebranes - in which
case you get strings that are tensionless for coincident fivebranes. Or
can you eat a cake and have it too?

Is your paper with Nati and Micha the paper where LST was first proposed?

Best
Lubos
__{_______________________________________________ _____________________________}
E-mail: lumo@matfyz.cz fax: +1-617/496-0110 Web: http://lumo.matfyz.cz/
eFax: +1-801/454-1858 work: +1-617/496-8199 home: +1-617/868-4487 (call)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Urs Schreiber

Jul21-04, 11:58 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 Wed, 21 Jul 2004, Lubos Motl wrote:\n\n> On Tue, 20 Jul 2004, Urs Schreiber wrote:\n>\n> > > non-Abelian 2-forms. Do you know that the little string theory is\n> > > non-local, for example?\n> >\n> > No, I didn\'t! :-)\n>\n> Maybe you just want to think about the (2,0) SCFT (superconformal field\n> theory)? It is the low energy limit of the type IIA little string theory,\n> and it is (as far as we believe) local. It has no 1/alpha\' strings of the\n> type I mentioned before (they are decoupled as very massive in the new\n> limit), but it has your cylindrical membrane-strings which must be\n> described by "some" non-Abelian 2-form potentials, whatever it is.\n>\n> Please distinguish (2,0) SCFT and LST. The former is a limit of M5-branes\n> in M-theory (low energies, coincident M5-branes, no scale), while the\n> latter are limits of NS5-branes in type II string theory and is richer and\n> non-local (and they have a fundamental string scale).\n\n\nHi Lubos, hi Moshe Rozali -\n\nthanks for all the helpful comments. I haven\'t yet found the time to read\nmore on LST (can anyone suggest a good overview?) but I dare ask a further\nquestion anyway:\n\nAs you pointed out (at least in some of the scenarios) one gets on a\n(stack of) 5-brane(s) a theory which contains (probably among other things\nlike open strings) closed strings that are boundaries of\ncylindrical 2-branes.\n\nNow these boundaries should come with an analog to a Chan-Paton factor,\nnamely a degree of freedom associated with the choice of 5-brane that the closed\nstring sits on. Right?\n\nOn the other hand, this is only a single such factor, since the other one\nsits on the closed string that is the other boundary of the cylindrical\n2-brane.\n\nThis would make sense to me, since the natural guess of boundary state\n(which is a closed string state of course) that describes a nonabelian\n2-form background takes values in the representation space of the gauge\ngroup (i.e. can be acted on by group elements), which would precisely correspond\nto such a single CP-like factor.\n\nAre such closed strings carrying CP factors discussed anywhere in the\nliterature?\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 Wed, 21 Jul 2004, Lubos Motl wrote:

> On Tue, 20 Jul 2004, Urs Schreiber wrote:
>
> > > non-Abelian 2-forms. Do you know that the little string theory is
> > > non-local, for example?
> >
> > No, I didn't! :-)
>
> Maybe you just want to think about the (2,0) SCFT (superconformal field
> theory)? It is the low energy limit of the type IIA little string theory,
> and it is (as far as we believe) local. It has no 1/\alpha' strings of the
> type I mentioned before (they are decoupled as very massive in the new
> limit), but it has your cylindrical membrane-strings which must be
> described by "some" non-Abelian 2-form potentials, whatever it is.
>
> Please distinguish (2,0) SCFT and LST. The former is a limit of M5-branes
> in M-theory (low energies, coincident M5-branes, no scale), while the
> latter are limits of NS5-branes in type II string theory and is richer and
> non-local (and they have a fundamental string scale).

Hi Lubos, hi Moshe Rozali -

thanks for all the helpful comments. I haven't yet found the time to read
more on LST (can anyone suggest a good overview?) but I dare ask a further
question anyway:

As you pointed out (at least in some of the scenarios) one gets on a
(stack of) 5-brane(s) a theory which contains (probably among other things
like open strings) closed strings that are boundaries of
cylindrical 2-branes.

Now these boundaries should come with an analog to a Chan-Paton factor,
namely a degree of freedom associated with the choice of 5-brane that the closed
string sits on. Right?

On the other hand, this is only a single such factor, since the other one
sits on the closed string that is the other boundary of the cylindrical
2-brane.

This would make sense to me, since the natural guess of boundary state
(which is a closed string state of course) that describes a nonabelian
2-form background takes values in the representation space of the gauge
group (i.e. can be acted on by group elements), which would precisely correspond
to such a single CP-like factor.

Are such closed strings carrying CP factors discussed anywhere in the
literature?

Moshe Rozali

Jul22-04, 02:28 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>Lubos,\n\nopen strings connecting D-branes, i.e. with Dirichlet boundary\ncondition on some toroidal direction, have also windings in that\ndirection- in the covering space they can connect any pair of images\nof the D-branes. This is of course required by T-duality, and the\nstatement I made (going back to BRS) is the M-theory obvious\ngeneralization.\n\nbest,\n\nMoshe\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>Lubos,

open strings connecting D-branes, i.e. with Dirichlet boundary
condition on some toroidal direction, have also windings in that
direction- in the covering space they can connect any pair of images
of the D-branes. This is of course required by T-duality, and the
statement I made (going back to BRS) is the M-theory obvious
generalization.

best,

Moshe