The BFSS matrix model (Banks-Fischler-Shenker-Susskind 96, Seiberg 97) is the description of the worldline dynamics of interacting D0-branes. In the large N limit of a large number of D0-branes this is supposed to encode the strong coupling limit of type IIA string theory known as M-theory at least in certain corners of its moduli space.
The BFSS model is a limiting case of the BMN matrix model, which improves on some of its shortcomings (see the Open problems below).
The BFSS matrix model was argued to arise in several seemingly rather different (but apparently secretly equivalent) ways:
as the worldline theory of a large number of D0-branes in type IIA string theory,
as the Kaluza-Klein compactification of 10d super Yang-Mills theory to 1+0 space dimensions,
as a certain non-commutative regularization of the light-cone gauge quantization of the Green-Schwarz sigma-model for the M2-brane (Nicolai-Helling 98, Dasgupta-Nicolai-Plefka 02).
In this picture matrix blocks around the diagonal correspond to blobs of membrane, while off-diagonal matrix elements correspond to thin tubes of membrane connecting these blobs.
graphics grabbed from Dasgupta-Nicolai-Plefka 02
In any case, the BFSS matrix model ends up being a quantum mechanical system whose bosonic degrees of freedom are a set of 9+1 large matrices. These play the role of would-be coordinate functions and their eigenvalues may be in interpreted as points in a non-commutative spacetime thus defined.
There is also the IKKT matrix model, which takes this one step further by reducing one dimension further down to D(-1)-branes in type IIB string theory.
See also at membrane matrix model.
In the 90s there was much excitement about the BFSS model, as people hoped it might provide a definition of M-theory. It is from these times that Edward Witten changed the original suggestion that “M” is for “magic, mystery and membrane” to the suggestion that it is for “magic, mystery and matrix”. (See Witten’s 2014 Kyoto prize speech, last paragraph.)
However, while the BFSS matrix model clearly sees something M-theoretic, just as clearly it is not the full answer. Notably it needs for its definition an ambient asympototic Minkowski background, a light cone limit and a peculiar scaling of string coupling over string length, all of which means that it pertains to a particular corner of a full theory.
From Nicolai-Helling 98, p. 2:
Despite the recent excitement, however, we do not think that M(atrix) theory and the $d= 11$ supermembrane in their present incarnation are already the final answer in the search for M-Theory, even though they probably are important pieces of the puzzle. There are still too many ingredients missing that we would expect the final theory to possess. For one thing, we would expect a true theory of quantum gravity to exhibit certain pregeometrical features corresponding to a “dissolution” of space-time and the emergence of some kind of non-commutative geometry at short distances; although the matrix model does achieve that to some extent by replacing commuting coordinates by non-commuting matrices, it seems to us that a still more radical departure from conventional ideas about space and time may be required in order to arrive at a truly background independent formulation (the matrix model “lives” in nine flat transverse dimensions only). Furthermore, there should exist some huge and so far completely hidden symmetries generalizing not only the duality symmetries of extended supergravity and string theory, but also the principles underlying general relativity.
Then, even assuming that in this corner all the crucial cohomological aspects of D-brane and M-brane charges (in twisted differential K-theory, twisted cohomotopy etc.) are secretly encoded in the matrix model, somehow, none of this is manifest, making the matrix model spit out numbers about a conceptually elusive theory in close analogy to how lattice QCD produces numbers without informing us about the actual conceptual nature of confined hadron physics.
A similar assessment has been given by Greg Moore, from pages 43-44 of his Physical Mathematics and the Future (here):
A good start $[$with defining M-theory$]$ was given by the Matrix theory approach of Banks, Fischler, Shenker and Susskind. We have every reason to expect that this theory produces the correct scattering amplitudes of modes in the 11-dimensional supergravity multiplet in 11-dimensional Minkowski space - even at energies sufficiently large that black holes should be created. (This latter phenomenon has never been explicitly demonstrated). But Matrix theory is only a beginning and does not give us the whole picture of M-theory. The program ran into increasing technical difficulties when more complicated compactifications were investigated. (For example, compactification on a six-dimensional torus is not very well understood at all. $[$…$]$). Moreover, to my mind, as it has thus far been practiced it has an important flaw: It has not led to much significant new mathematics.
If history is a good guide, then we should expect that anything as profound and far-reaching as a fully satisfactory formulation of M-theory is surely going to lead to new and novel mathematics. Regrettably, it is a problem the community seems to have put aside - temporarily. But, ultimately, Physical Mathematics must return to this grand issue.
There are furcher technical open issues, such as the open question whether the theory has a decent ground state the way it needs to have to make sense (see the references below).
The original articles are
Tom Banks, Willy Fischler, Stephen Shenker, Leonard Susskind, M Theory As A Matrix Model: A Conjecture, Phys. Rev. D55 (1997). (arXiv:hep-th/9610043)
Leonard Susskind, Another Conjecture about M(atrix) Theory (arXiv:https://arxiv.org/abs/hep-th/9704080)
Ashoke Sen, D0 Branes on $T^n$ and Matrix Theory, Adv. Theor. Math. Phys.2:51-59, 1998 (arXiv:hep-th/9709220)
Nathan Seiberg, Why is the Matrix Model Correct?, Phys. Rev. Lett. 79:3577-3580, 1997 (arXiv:hep-th/9710009)
Review includes
Tom Banks, Matrix Theory, Nucl.Phys.Proc.Suppl. 67 (1998) 180-224 (arXiv:hep-th/9710231)
Washington Taylor, M(atrix) Theory: Matrix Quantum Mechanics as a Fundamental Theory, Rev. Mod. Phys. 73:419-462, 2001 (arXiv:hep-th/0101126)
A review of further developments is in
See also
Discussion as a solution to the open problem of defining M-theory is in
where it says:
A good start was given by the Matrix theory approach of Banks, Fischler, Shenker and Susskind. We have every reason to expect that this theory produces the correct scattering amplitudes of modes in the 11-dimensional supergravity multiplet in 11-dimensional Minkowski space - even at energies sufficiently large that black holes should be created. (This latter phenomenon has never been explicitly demonstrated). But Matrix theory is only a beginning and does not give us the whole picture of M-theory. The program ran into increasing technical difficulties when more complicated compactifications were investigated. (For example, compactification on a six-dimensional torus is not very well understood at all. $[...]$). Moreover, to my mind, as it has thus far been practiced it has an important flaw: It has not led to much significant new mathematics.
If history is a good guide, then we should expect that anything as profound and far-reaching as a fully satisfactory formulation of M-theory is surely going to lead to new and novel mathematics. Regrettably, it is a problem the community seems to have put aside - temporarily. But, ultimately, Physical Mathematics must return to this grand issue.
Derivation from open string field theory is discussed in
Relation to the 6d (2,0)-supersymmetric QFT:
The Poisson bracket-formulation of the classical light-cone gauge Hamiltonian for the bosonic relativistic membrane and the corresponding matrix commutator regularization is due to:
On the regularized light-cone gauge quantization of the Green-Schwarz sigma model for the M2-brane on (super) Minkowski spacetime, yielding the BFSS matrix model:
Original articles:
Observation that the spectrum is continuous:
Review:
Hermann Nicolai, Robert Helling, Supermembranes and M(atrix) Theory, In Trieste 1998, Nonperturbative aspects of strings, branes and supersymmetry 29-74 (arXiv:hep-th/9809103, spire:476366)
Jens Hoppe, Membranes and Matrix Models (arXiv:hep-th/0206192)
Arundhati Dasgupta, Hermann Nicolai, Jan Plefka, An Introduction to the Quantum Supermembrane, Grav. Cosmol. 8:1, 2002; Rev. Mex. Fis. 49S1:1-10, 2003 (arXiv:hep-th/0201182)
Gijs van den Oord, On Matrix Regularisation of Supermembranes, 2006 (pdf)
The generalization to pp-wave spacetimes (leading to the BMN matrix model):
Keshav Dasgupta, Mohammad Sheikh-Jabbari, Mark Van Raamsdonk, Section 2 of: Matrix Perturbation Theory For M-theory On a PP-Wave, JHEP 0205:056, 2002 (arXiv:hep-th/0205185)
Keshav Dasgupta, Mohammad Sheikh-Jabbari, Mark Van Raamsdonk, Section 2 of: Matrix Perturbation Theory For M-theory On a PP-Wave, JHEP 0205:056, 2002 (arXiv:hep-th/0205185)
See also
Mike Duff, T. Inami, Christopher Pope, Ergin Sezgin, Kellogg Stelle, Semiclassical Quantization of the Supermembrane, Nucl.Phys. B297 (1988) 515-538 (spire:247064)
Daniel Kabat, Washington Taylor, section 2 of: Spherical membranes in Matrix theory, Adv. Theor. Math. Phys. 2: 181-206, 1998 (arXiv:hep-th/9711078)
Nathan Berkovits, Towards Covariant Quantization of the Supermembrane (arXiv:hep-th/0201151)
Qiang Jia, On matrix description of D-branes (arXiv:1907.00142)
Discussion of light cone longitudal M5-branes in the BFSS matrix model (for light cone transversal M5-s see at BMN matrix model):
Tom Banks, Nathan Seiberg, Stephen Shenker, Branes from Matrices, Nucl. Phys. B490:91-106, 1997 (arXiv:hep-th/9612157)
Judith Castelino, Sangmin Lee, Washington Taylor, Longitudinal 5-branes as 4-spheres in Matrix theory, Nucl. Phys. B526:334-350, 1998 (arXiv:hep-th/9712105)
(introducing the fuzzy 4-sphere)
There remains the problem of existence of a sensible ground state of the BFSS model.
For a new attempt at solving this problem, and for pointers to previous attempts see
L. Boulton, M.P. Garcia del Moral, A. Restuccia, The ground state of the D=11 supermembrane and matrix models on compact regions, Nuclear Physics B Volume 910, September 2016, Pages 665-684 (arXiv:1504.04071)
L. Boulton, M.P. Garcia del Moral, A. Restuccia, Measure of the potential valleys of the supermembrane theory, Physics Letters B Volume 797, 2019, 134873 (arXiv:1811.05758)
Computation of graviton scattering amplitudes:
Katrin Becker, Melanie Becker, A Two-Loop Test of M(atrix) Theory, Nucl.Phys. B506 (1997) 48-60 (arXiv:hep-th/9705091)
Katrin Becker, Melanie Becker, Joseph Polchinski, Arkady Tseytlin, Higher Order Graviton Scattering in M(atrix) Theory, Phys.Rev.D56:3174-3178,1997 (arXiv:hep-th/9706072)
also Kabat-Taylor 97
M. Fabbrichesi, Graviton scattering in matrix theory and supergravity, in: Ceresole A., Kounnas C., Dieter Lüst, Stefan Theisen (eds.) Quantum Aspects of Gauge Theories, Supersymmetry and Unification, Lecture Notes in Physics, vol 525. Springer, Berlin, Heidelberg (arXiv:hep-th/9811204)
Robert Helling, Jan Plefka, Marco Serone, Andrew Waldron, Three-graviton scattering in M-theory, Nuclear Physics B Volume 559, Issues 1–2, 18 October 1999, Pages 184-204 (arXiv:hep-th/9905183)
Robert Echols, M-theory, supergravity and the matrix model: Graviton scattering and non-renormalization theorems, PhD thesis, 1999 pdf
Relation to black holes in string theory:
Tom Banks, Willy Fischler, Igor Klebanov, Leonard Susskind, Schwarzschild Black Holes from Matrix Theory, Phys.Rev.Lett.80:226-229,1998 (arXiv:hep-th/9709091)
Tom Banks, Willy Fischler, Igor Klebanov, Leonard Susskind, Schwarzchild Black Holes in Matrix Theory II, JHEP 9801:008,1998 (arXiv:hep-th/9711005)
Igor Klebanov, Leonard Susskind, Schwarzschild Black Holes in Various Dimensions from Matrix Theory, Phys.Lett.B416:62-66,1998 (arXiv:hep-th/9709108)
Edi Halyo, Six Dimensional Schwarzschild Black Holes in M(atrix) Theory (arXiv:hep-th/9709225)
Gary Horowitz, Emil Martinec, Comments on Black Holes in Matrix Theory, Phys. Rev. D 57, 4935 (1998) (arXiv:hep-th/9710217)
Daniel Kabat, Washington Taylor, Spherical membranes in Matrix theory, Adv.Theor.Math.Phys.2:181-206,1998 (arXiv:hep-th/9711078)
Yoshifumi Hyakutake, Black Hole and Fuzzy Objects in BFSS Matrix Model (arXiv:1801.07869)
Haoxing Du, Vatche Sahakian, Emergent geometry from stochastic dynamics, or Hawking evaporation in M(atrix) theory (arXiv:1812.05020)
(combination with random matrix theory)
Relation to lattice gauge theory and numerical tests of AdS/CFT:
Anosh Joseph, Review of Lattice Supersymmetry and Gauge-Gravity Duality (arXiv:1509.01440)
Veselin G. Filev, Denjoe O’Connor, The BFSS model on the lattice, JHEP 1605 (2016) 167 (arXiv:1506.01366)
Masanori Hanada, What lattice theorists can do for superstring/M-theory, International Journal of Modern Physics AVol. 31, No. 22, 1643006 (2016) (arXiv:1604.05421)
On AdS/CFT in the form of AdS2/CFT1 with the BFSS matrix model on the CFT side and black hole-like solutions in type IIA supergravity on the AdS side:
and concerning the analog of its holographic entanglement entropy:
Last revised on January 18, 2020 at 16:21:10. See the history of this page for a list of all contributions to it.