what is m-theory? [Archive]

aekanshchumber

Aug18-04, 01:17 PM

hello,
being new to the m-theory i don't know much about it,beside some basics and some postulates. i'd be thankful if someone help me to understand it, like 7-dimensions beyond 4-d of space and time, mathematics behind it.

thanks
Aekansh

Urs Schreiber

Aug18-04, 02:03 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>"aekanshchumber" <aekansh_s@yahoo.com> schrieb im Newsbeitrag\nnews:aekanshchumber.1b73ls-100000@physicsforums.com...\n\n> being new to the m-theory i don\'t know much about it\n\nHave a look at the section "popular resources" on our group\'s homepage\n\nhttp://schwinger.harvard.edu/~motl/sps/ .\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>"aekanshchumber" <aekansh_s@yahoo.com> schrieb im Newsbeitrag
news:aekanshchumber.1b73ls-100000@physicsforums.com...

> being new to the m-theory i don't know much about it

Have a look at the section "popular resources" on our group's homepage

http://schwinger.harvard.edu/~motl/sps/ .

Brian J Flanagan

Aug19-04, 12:23 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>aekanshchumber wrote:\n\n> being new to the m-theory i don\'t know much about it, beside\n> some basics and some postulates. i\'d be thankful if someone help me to\n> understand it, like 7-dimensions beyond 4-d of space and time,\n> mathematics behind it.\n\nHere are some nice introductory texts:\n\nhttp://www.theory.caltech.edu/people/jhs/strings/\n\nhttp://encyclopedia.thefreedictionary.com/Brane\n\nhttp://theory.itp.ucsb.edu/~joep/audio.html\n\n____________________________________ _\n\n\nHere are a few wonderful texts for general background -- a bit more\nadvanced material:\n\nAnalysis, Manifolds and Physics, by Yvonne Choquet-Bruhat, Cecile\nDewitt-Morette, M. Dillard-Bleick. Elsevier (2001) (A miracle of\nlucidity -- I regard this work as a modern classic.)\n\nGockeler, M. and Schucker, T. Differential geometry, gauge theories,\nand gravity. Cambridge, 1987. (Rather abstract, but offering an\naustere beauty and a feeling for the essentials.)\n\nNash, Charles, and Siddhartha Sen. Topology and Geometry for\nPhysicists. London: Academic Press, 1983.\n\n____________. Differential Topology and Quantum Field Theory. London,\nAcademic Press, 1991. (I imagine these gents are wonderful teachers.)\n\nT. Applequist, A Chodos, and P. Freund, eds. Modern Kaluza-Klein\nTheories, (Addison Wesley, Menlo Park, 1987).\n\n____________________________\n\nString & M-theory\n\nGreen, MB, JH Schwarz, and E Witten. Superstring Theory. New York, NY:\nCambridge University Press, 1987. [classic early text]\n\nPolchinski, Joseph. String Theory, 1 & 2, Cambridge\n\nhttp://www.lns.cornell.edu/spr/2001-07/msg0033951.html\n\nhttp://www.damtp.cam.ac.uk/db/pub.ppdb/ppdbls.pl?action=list&Name=Green&format=HTML&title=Preprints:+Michael+B.+Green\n\n_____________ ________________\n\n\nThe following is excerpted from an interview with Ed Witten, which you\ncan find here:\n\nhttp://superstringtheory.com/people/witten.html\n\nWhat is M theory?\n\nM theory is a name for a more unified theory that has the different\nstring theories, as we know them, as limits, and which also can\nreduce, under appropriate conditions, to eleven-dimensional\nsupergravity. There\'s this picture that we all have to draw where\ndifferent string theories are limits of this M theory, where M stands\nfor Magic, Mystery or Matrix, but it also sometimes is seen as\nstanding for Murky, because the truth about M theory is Murky. And the\ndifferent limits, where the main parameter simplifies, give the\ndifferent string theories -- Type IIA, Type IIB, Type I, and there\'s\neleven-dimensional supergravity, which turns out to be an important\nlimit even though it isn\'t part of the systematic perturbation\nexpansion, then there\'s the E8XE8 heterotic string, and there\'s SO(32)\nheterotic string.\nSo M-theory is a name for this picture, this more general picture that\nwill generate the different limits through the different string\ntheories. The parameters in this picture we can think of being roughly\nhbar, which is Planck\'s constant, and that determines how important\nthe quantum effects are, and the other parameter is alpha prime, which\nis the tension, related to the tension of the string, that determines\nhow important stringy effects are. So traditionally, a physicist\nlooking at Type IIA, for example, by traditional weak coupling\nmethods, explores this little region, and if asked how his theory is\nrelated to Type I theory, the answer would have to be, "Well I don\'t\nknow, that\'s something else."\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>aekanshchumber wrote:

> being new to the m-theory i don't know much about it, beside
> some basics and some postulates. i'd be thankful if someone help me to
> understand it, like 7-dimensions beyond 4-d of space and time,
> mathematics behind it.

Here are some nice introductory texts:

http://www.theory.caltech.edu/people/jhs/strings/

http://encyclopedia.thefreedictionary.com/Brane

http://theory.itp.ucsb.edu/~joep/audio.html

__{___________________________________}

Here are a few wonderful texts for general background -- a bit more
advanced material:

Analysis, Manifolds and Physics, by Yvonne Choquet-Bruhat, Cecile
Dewitt-Morette, M. Dillard-Bleick. Elsevier (2001) (A miracle of
lucidity -- I regard this work as a modern classic.)

Gockeler, M. and Schucker, T. Differential geometry, gauge theories,
and gravity. Cambridge, 1987. (Rather abstract, but offering an
austere beauty and a feeling for the essentials.)

Nash, Charles, and Siddhartha Sen. Topology and Geometry for
Physicists. London: Academic Press, 1983.

__{__________}. Differential Topology and Quantum Field Theory. London,
Academic Press, 1991. (I imagine these gents are wonderful teachers.)

T. Applequist, A Chodos, and P. Freund, eds. Modern Kaluza-Klein
Theories, (Addison Wesley, Menlo Park, 1987).

__{__________________________}

String & M-theory

Green, MB, JH Schwarz, and E Witten. Superstring Theory. New York, NY:
Cambridge University Press, 1987. [classic early text]

Polchinski, Joseph. String Theory, 1 & 2, Cambridge

http://www.lns.cornell.edu/spr/2001-07/msg0033951.html

http://www.damtp.cam.ac.uk/db/pub.ppdb/ppdbls.pl?action=list&Name=Green&format=HTML&title=Preprints:+Michael+B.+Green

__{___________________________}

The following is excerpted from an interview with Ed Witten, which you
can find here:

http://superstringtheory.com/people/witten.html

What is M theory?

M theory is a name for a more unified theory that has the different
string theories, as we know them, as limits, and which also can
reduce, under appropriate conditions, to eleven-dimensional
supergravity. There's this picture that we all have to draw where
different string theories are limits of this M theory, where M stands
for Magic, Mystery or Matrix, but it also sometimes is seen as
standing for Murky, because the truth about M theory is Murky. And the
different limits, where the main parameter simplifies, give the
different string theories -- Type IIA, Type IIB, Type I, and there's
eleven-dimensional supergravity, which turns out to be an important
limit even though it isn't part of the systematic perturbation
expansion, then there's the E8XE8 heterotic string, and there's SO(32)
heterotic string.
So M-theory is a name for this picture, this more general picture that
will generate the different limits through the different string
theories. The parameters in this picture we can think of being roughly
\hbar, which is Planck's constant, and that determines how important
the quantum effects are, and the other parameter is \alpha prime, which
is the tension, related to the tension of the string, that determines
how important stringy effects are. So traditionally, a physicist
looking at Type IIA, for example, by traditional weak coupling
methods, explores this little region, and if asked how his theory is
related to Type I theory, the answer would have to be, "Well I don't
know, that's something else."