group cohomology, nonabelian group cohomology, Lie group cohomology
cohomology with constant coefficients / with a local system of coefficients
differential cohomology
Recall that geometric T-duality is an operation acting on tuples roughly consisting of
a smooth manifold with the structure of a torus-principal bundle – modelling spacetime
equipped with a circle 2-bundle with connection – modelling the Kalb-Ramond field
and in twisted K-theory refined to elements in differential twisted K-theory – modelling the RR-field
and notably equipped with a (pseudo)Riemannian metric – modelling the field of gravity.
The idea of topological T-duality (due to Bouwknegt-Evslin-Mathai 04, Bouwknegt-Hannabus-Mathai 04) is to disregard the Riemannian metric and the connection and study the remaining “topological” structure.
While the idea of T-duality originates in string theory, topological T-duality has become a field of study in pure mathematics in its own right.
In the language of bi-branes a topological T-duality transformation is a bi-brane of a special kind between the two gerbes involved. The induced integral transform (on sheaves of sections of, or K-classes of) (twisted) vector bundles is essentially the Fourier-Mukai transformation. More on the bi-brane interpretation of (topological and non-topological) T-duality is in (Sarkissian-Schweigert 08).
Two tuples consisting of a -bundle over a manifold and a line bundle gerbe over are topological T-duals if there exists an isomorphism of the two bundle gerbes pulled back to the fiber product correspondence space :
of a certain prescribed integral transform-form (Bunke-Rumpf-Schick 08, p. 9)).
topological T-duality
The concept of topological T-duality was introduced on the level of differential form-data in
Peter Bouwknegt, Jarah Evslin, Varghese Mathai, T-Duality: Topology Change from H-flux, Commun. Math. Phys. 249:383-415, 2004 [hep-th/0306062, doi:10.1007/s00220-004-1115-6]
Peter Bouwknegt, Keith Hannabus, Varghese Mathai, T-duality for principal torus bundles, JHEP 0403 (2004) 018 (hep-th/0312284)
In these papers the -gerbe (circle 2-bundle with connection) does not appear, but an integral differential 3-form, representing its Dixmier-Douady class does. Note that if the integral cohomology group of has torsion in dimension three, not all gerbes will arise in this way.
The formalization with the above topological/homotopy theoretic data originates in
Ulrich Bunke, Thomas Schick, On the topology of T-duality, Rev. Math. Phys. 17 (2005) 77-112 [arXiv:math/0405132, doi:10.1142/S0129055X05002315]
U. Bunke, P. Rumpf, Thomas Schick, The topology of -duality for -bundles, Rev. Math. Phys. 18 1103 (2006) [arXiv:math.GT/0501487, doi:10.1142/S0129055X06002875]
Ulrich Bunke, Markus Spitzweck, Thomas Schick, Periodic twisted cohomology and T-duality, Astérisque No. 337 (2011), vi+134 pp. ISBN: 978-2-85629-307-2
A refined version of this using smooth stacks is due to
Ulrich Bunke, Thomas Nikolaus: T-Duality via Gerby Geometry and Reductions, Reviews in Mathematical Physics 27 05 1550013 (2015) [arXiv:1305.6050, doi:10.1142/S0129055X15500130]
Thomas Nikolaus, T-Duality in K-theory and Elliptic Cohomology, talk at String Geometry Network Meeting, Feb 2014, ESI Vienna (website)
There is also C*-algebraic version of toplogical T-duality, .e. in noncommutative topology, which sees also topological T-duals in non-commutative geometry:
The equivalence of the C*-algebraic to the Bunke-Schick version, when the latter exists, is discussed in
Introduction and review:
Jonathan Rosenberg, Topology, -algebras, and string duality, Regional Conference Series in Mathematics 111, Amer. Math. Soc. (2009) [doi:10.1090/cbms/111, ZMATH]
§1 in Waldorf 2022
Another discussion that instead of noncommutative geometry uses topological groupoids is in
Comments in relation to T-folds:
The bi-brane perspective on T-duality is amplified in
Discussion for non-free torus actions (physically: KK-monopoles) is in
Discussion in rational homotopy theory/dg-geometry is in
and a derivation of the rules of topological T-duality from analysis of the super p-brane super-cocycles in super rational homotopy theory (with a doubled supergeometry) is given in
reviewed in
Domenico Fiorenza, Hisham Sati, Urs Schreiber, T-duality in rational homotopy theory via strong homomotopy Lie algebras, Geometry, Topology and Mathematical Physics Journal, Volume 1 (2018) (arXiv:1712.00758)
Domenico Fiorenza, T-duality in rational homotopy theory, talk at 38th Srni Winter School on Geometry and Physics, 2018 (pdf slides)
and further expanded on on
See also:
Comprehensive discussion in higher differential geometry:
Luigi Alfonsi, Global Double Field Theory is Higher Kaluza-Klein Theory, Fortsch. d. Phys. 2020 (arXiv:1912.07089, doi:10.1002/prop.202000010)
(relating Kaluza-Klein compactification on principal ∞-bundles to double field theory, T-folds, non-abelian T-duality, type II geometry, exceptional geometry, …)
Luigi Alfonsi, The puzzle of global Double Field Theory: open problems and the case for a Higher Kaluza-Klein perspective (arXiv:2007.04969)
Discussion in the equivariant generality, ie. as an equivalence of twisted equivariant K-theory groups:
On possible geometric refinement of topological T-duality via some form of differential cohomology:
via differential K-theory classes:
using adjusted principal 2-connections:
Hyungrok Kim, Christian Saemann, Non-Geometric T-Duality as Higher Groupoid Bundles with Connections [arXiv:2204.01783]
Konrad Waldorf: Geometric T-duality: Buscher rules in general topology, Ann. Henri Poincaré 25 (2024) 1285–1358 [arXiv:2207.11799, doi:10.1007/s00023-023-01295-0]
Hyungrok Kim, Christian Saemann, T-duality as Correspondences of Categorified Principal Bundles with Adjusted Connections [arXiv:2303.16162]
Last revised on October 15, 2024 at 07:28:10. See the history of this page for a list of all contributions to it.