Type II string theory

String theory
Fundamental objects
String Brane D-brane
Perturbative theory
Bosonic Superstring Type I Type II (IIA / IIB) Heterotic (SO(32) · E8×E8)
Non-perturbative results
S-duality T-duality M-theory AdS/CFT correspondence
Phenomenology
Phenomenology Cosmology Landscape
Mathematics
Mirror symmetry Monstrous moonshine
Related concepts Conformal field theory Quantum gravity Supersymmetry Supergravity Twistor string theory Kaluza–Klein theory Holographic principle Theory of everything
Theorists Arkani-Hamed Banks Dijkgraaf Duff Fischler Gates Gliozzi Green Greene Gross Gubser Harvey Hořava Kaku Klebanov Kontsevich Linde Maldacena Mandelstam Martinec Minwalla Moore Motl Nekrasov Neveu Olive Polchinski Polyakov Ramond Randall Rohm Scherk Schwarz Seiberg Sen Shenker Sơn Strominger Sundrum Susskind 't Hooft Townsend Vafa Veneziano E. Verlinde H. Verlinde Witten Yau Zaslow
History Glossary

In theoretical physics, type II string theory is a unified term that includes both type IIA strings and type IIB strings theories. Type II string theory accounts for two of the five consistent superstring theories in ten dimensions. Both theories have the maximal amount of supersymmetry — namely 32 supercharges — in ten dimensions. Both theories are based on oriented closed strings. On the worldsheet, they differ only in the choice of GSO projection.

Type IIA string

At low energies, type IIA string theory is described by type IIA supergravity in ten dimensions which is a non-chiral theory (i.e. left-right symmetric) with (1,1) d=10 supersymmetry; the fact that the anomalies in this theory cancel is therefore trivial.

In the 1990s it was realized by Edward Witten (building on previous insights by Michael Duff, Paul Townsend, and others) that the limit of type IIA string theory in which the string coupling goes to infinity becomes a new 11-dimensional theory called M-theory.^[1]

The mathematical treatment of type IIA string theory belongs to symplectic topology and algebraic geometry, particularly Gromov–Witten invariants.

Type IIB string

At low energies, type IIB string theory is described by type IIB supergravity in ten dimensions which is a chiral theory (left-right asymmetric) with (2,0) d=10 supersymmetry; the fact that the anomalies in this theory cancel is therefore nontrivial.

In the 1990s it was realized that type II string theory with the string coupling constant g is equivalent to the same theory with the coupling 1/g. This equivalence is known as S-duality.

Orientifold of type IIB string theory leads to type I string theory.

The mathematical treatment of type IIB string theory belongs to algebraic geometry, specifically the deformation theory of complex structures originally studied by Kunihiko Kodaira and Donald C. Spencer.

In 1997 Juan Maldacena gave some arguments indicating that type IIB string theory is equivalent to a Supersymmetric Yang Mills theory with 4 supersymmetries and gauge group SU(N), in the 't Hooft limit; it was the first suggestion concerning the AdS/CFT correspondence.^[2]

Relationship between the type II theories

In the late 1980s, it was realized that type IIA string theory is related to type IIB string theory by T-duality.

See also

• Superstring theory
• Type I string
• Heterotic string

References

String theory
Background	Strings History of string theory First superstring revolution Second superstring revolution String theory landscape
Theory	Nambu–Goto action Polyakov action Bosonic string theory Superstring theory Type I string Type II string Type IIA string theory Type IIB string theory Heterotic string N=2 superstring F-theory String field theory Matrix string theory Non-critical string theory Nonlinear sigma model Tachyon condensation RNS formalism GS formalism
String Duality	T-duality S-duality U-duality Montonen–Olive duality Mysterious duality
Particles and Fields	Graviton Dilaton Tachyon Ramond–Ramond field Kalb–Ramond field Magnetic monopole Dual graviton Dual photon
Branes	D-brane NS5-brane M2-brane M5-brane S-brane Black brane Black holes Black string Brane cosmology Quiver diagram Hanany–Witten transition
Conformal Field Theory	Virasoro algebra Mirror symmetry Conformal anomaly Conformal algebra Superconformal algebra Vertex operator algebra Loop algebra Kac–Moody algebra Wess–Zumino–Witten model
Gauge Theory	Anomalies Instantons Chern–Simons form Bogomol'nyi–Prasad–Sommerfield bound Exceptional Lie groups (G2, F4, E6, E7, E8) ADE classification Dirac string p-form electrodynamics
Geometry	Kaluza–Klein theory Compactification Why 10 dimensions? Kähler manifold Ricci-flat manifold Calabi–Yau manifold Hyperkähler manifold K3 surface G2 manifold Spin(7) manifold Generalized complex manifold Orbifold Conifold Orientifold Moduli space Hořava–Witten domain wall K-theory (physics) Twisted K-theory
Supersymmetry	Supergravity Superspace Lie superalgebra Lie supergroup
Holography	Holographic principle AdS/CFT correspondence
M-theory	Matrix theory Introduction to M-theory
String theorists	Nima Arkani-Hamed Michael Francis Atiyah Tom Banks David Berenstein Raphael Bousso Gerald Cleaver Thomas Curtright Robbert Dijkgraaf Jacques Distler Michael Douglas Michael Duff Sergio Ferrara Willy Fischler Daniel Friedan Sylvester James Gates Ferdinando Gliozzi Rajesh Gopakumar Michael Green Brian Greene David Gross Steven Gubser Sergei Gukov Jeffrey Harvey Petr Hořava Gary Gibbons Shamit Kachru Michio Kaku Renata Kallosh Theodor Kaluza Anton Kapustin Igor Klebanov Vadim Knizhnik Maxim Kontsevich Oskar Klein Andrei Linde Juan Maldacena Stanley Mandelstam Donald Marolf Emil Martinec Shiraz Minwalla Gregory Moore Lubos Motl Sunil Mukhi Robert Myers Dimitri Nanopoulos Asad Naqvi Horatiu Nastase Nikita Nekrasov André Neveu Holger Bech Nielsen Peter van Nieuwenhuizen Sergei Novikov David Olive Hirosi Ooguri Joseph Polchinski Alexander Polyakov Arvind Rajaraman Pierre Ramond Lisa Randall Seifallah Randjbar-Daemi Martin Roček Ryan Rohm Joël Scherk John H. Schwarz Nathan Seiberg Ashoke Sen Steve Shenker Warren Siegel Eva Silverstein Đàm Thanh Sơn Matthias Staudacher Andrew Strominger Raman Sundrum Leonard Susskind Gerard 't Hooft Paul Townsend Sandip Trivedi Cumrun Vafa Gabriele Veneziano Erik Verlinde Herman Verlinde Julius Wess Edward Witten Shing-Tung Yau Tamiaki Yoneya Alexander Zamolodchikov Alexei Zamolodchikov Eric Zaslow Bruno Zumino Barton Zwiebach