Project acronym TQFT
Project The geometry of topological quantum field theories
Researcher (PI) Katrin Wendland
Host Institution (HI) ALBERT-LUDWIGS-UNIVERSITAET FREIBURG
Call Details Starting Grant (StG), PE1, ERC-2007-StG
Summary The predictive power of quantum field theory (QFT) is a perpetual driving force in geometry. Examples include the invention of Frobenius manifolds, mixed twistor structures, primitive forms, and harmonic bundles, up to the discovery of the McKay correspondence, mirror symmetry, and Gromov-Witten invariants. Still seemingly disparate, in fact these all are related to topological (T) QFT and thereby to the work by Cecotti, Vafa et al of more than 20 years ago. The broad aim of the proposed research is to pull the strands together which have evolved from TQFT, by implementing insights from mathematics and physics. The goal is a unified, conclusive picture of the geometry of TQFTs. Solving the fundamental questions on the underlying common structure will open new horizons for all disciplines built on TQFT. Hertling’s “TERP” structures, formally unifying the geometric ingredients, will be key. The work plan is textured into four independent strands which gain full power from their intricate interrelations. (1) To implement TQFT, a construction by Hitchin will be generalised to perform geometric quantisation for spaces with TERP structure. Quasi-classical limits and conformal blocks will be studied as well as TERP structures in the Barannikov-Kontsevich construction of Frobenius manifolds. (2) Relating to singularity theory, a complete picture is aspired, including matrix factorisation and allowing singularities of functions on complete intersections. A main new ingredient are QFT results by Martinec and Moore. (3) Incorporating D-branes, spaces of stability conditions in triangulated categories will be equipped with TERP structures. To use geometric quantisation is a novel approach which should solve the expected convergence issues. (4) For Borcherds automorphic forms and GKM algebras their as yet cryptic relation to “generalised indices” shall be demystified: In a geometric quantisation of TERP structures, generalised theta functions should appear naturally.
Summary
The predictive power of quantum field theory (QFT) is a perpetual driving force in geometry. Examples include the invention of Frobenius manifolds, mixed twistor structures, primitive forms, and harmonic bundles, up to the discovery of the McKay correspondence, mirror symmetry, and Gromov-Witten invariants. Still seemingly disparate, in fact these all are related to topological (T) QFT and thereby to the work by Cecotti, Vafa et al of more than 20 years ago. The broad aim of the proposed research is to pull the strands together which have evolved from TQFT, by implementing insights from mathematics and physics. The goal is a unified, conclusive picture of the geometry of TQFTs. Solving the fundamental questions on the underlying common structure will open new horizons for all disciplines built on TQFT. Hertling’s “TERP” structures, formally unifying the geometric ingredients, will be key. The work plan is textured into four independent strands which gain full power from their intricate interrelations. (1) To implement TQFT, a construction by Hitchin will be generalised to perform geometric quantisation for spaces with TERP structure. Quasi-classical limits and conformal blocks will be studied as well as TERP structures in the Barannikov-Kontsevich construction of Frobenius manifolds. (2) Relating to singularity theory, a complete picture is aspired, including matrix factorisation and allowing singularities of functions on complete intersections. A main new ingredient are QFT results by Martinec and Moore. (3) Incorporating D-branes, spaces of stability conditions in triangulated categories will be equipped with TERP structures. To use geometric quantisation is a novel approach which should solve the expected convergence issues. (4) For Borcherds automorphic forms and GKM algebras their as yet cryptic relation to “generalised indices” shall be demystified: In a geometric quantisation of TERP structures, generalised theta functions should appear naturally.
Max ERC Funding
750 000 €
Duration
Start date: 2009-01-01, End date: 2014-06-30
Project acronym UB12
Project Ergodic Group Theory
Researcher (PI) Uri Bader
Host Institution (HI) WEIZMANN INSTITUTE OF SCIENCE
Call Details Starting Grant (StG), PE1, ERC-2012-StG_20111012
Summary "The aim of the proposed research is gaining a better understanding of locally compact groups and their lattices. Our tools are mainly ergodic theoretical.
We propose a variety of novel ideas that open new horizons for research.
The first meta idea is the adoption of tools from the semi-simple theory in order to apply them for general locally compact groups. In particular, we suggest a construction of a ""Weyl group"" and an abstract definition of rank for every locally compact group. We are able to construct a ""Coxeter complex"" and we foresee a construction of a ""building like"" object.
A second set of ideas concerns the category of measure equivalences, which is a natural generalization of the notion of a lattice in a group. This category is long known to be a measurable counterpart of the better studied category of quasi-isometries, yet it misses a good definition of self measure equivalences of an object, analog to the group of quasi-isometries.
We suggest such a definition, and propose to study it, among a variety of related constructions.
A full implementation of our ideas requires a better understanding of locally compact groups.
Thus, an important aspect of the proposed research is that it leaves plenty of room for the study of specific examples and test cases."
Summary
"The aim of the proposed research is gaining a better understanding of locally compact groups and their lattices. Our tools are mainly ergodic theoretical.
We propose a variety of novel ideas that open new horizons for research.
The first meta idea is the adoption of tools from the semi-simple theory in order to apply them for general locally compact groups. In particular, we suggest a construction of a ""Weyl group"" and an abstract definition of rank for every locally compact group. We are able to construct a ""Coxeter complex"" and we foresee a construction of a ""building like"" object.
A second set of ideas concerns the category of measure equivalences, which is a natural generalization of the notion of a lattice in a group. This category is long known to be a measurable counterpart of the better studied category of quasi-isometries, yet it misses a good definition of self measure equivalences of an object, analog to the group of quasi-isometries.
We suggest such a definition, and propose to study it, among a variety of related constructions.
A full implementation of our ideas requires a better understanding of locally compact groups.
Thus, an important aspect of the proposed research is that it leaves plenty of room for the study of specific examples and test cases."
Max ERC Funding
1 150 000 €
Duration
Start date: 2012-09-01, End date: 2018-08-31
