(in Polish) Duality, descent and defects: The higher geometry and category theory of charged dynamics 1100-DDD
The goal of this two-semester lecture course is an in-depth introduction into the conceptual framework and methodology of higher geometry and algebra employed in the modern study of phenomena involving dynamical (extended) distributions of (topological) charge -— from the definition of Dirac-Feynman amplitudes for charged dynamics in nontrivial spacetime and configurational topologies in terms of differential characters and a hierarchical geometrisation of the integral cohomology classes of the corresponding gauge fields (in the form of n-gerbes), through categorification of quantum-mechanically consistent symmetries and the universal (higher) gauge principle for symmetries modelled on group and groupoid actions and on more general correspondences (with a homological description of anomalies and classification of inequivalent reductions), all the way up to a realisation of dualities by topological defects, construction of simplicial field theories over defect-stratified spacetimes and the corresponding higher categorial structures on the configuration bundle.
Below, we give a (more) detailed outline of the course:
- A lightning introduction to/review of
- the theory of Lie groupoids and algebroids (axiomatics, examples, the group of bisections and its actions), the Cartan-type calculus, groupoid modules and orbispaces;
- the theory of fibre bundles with connective structure: vector bundles with Koszul connections, principal bundles with principal connection 1-forms and associated bundles with Crittenden connections, reduction and prolongation (generalised Stieffel-Whitney classes);
- rudiments of category theory (universality, representability and internalisation) and homological algebra (Čech and de Rham cohomology, sheaf cohomology, Dupont's simplicial cohomology, hypercohomology, Lie-algebra and group cohomology).
- Murray's gerbes — from the lifting gerbe and the Beilinson-Deligne hypercohomology to (weak) higher categories, via (simplicial) higher geometry. The (higher) Aharonov-Bohm effect and beyond.
- Classical field theory with tensorial resp. simplicial couplings (using the Beilinson-Deligne hypercohomology and its Cheeger-Simons model). Dirac-Feynman amplitudes, the Tulczyjew-Gawędzki-Kijowski-Szczyrba(s) first-order formalism and prequantisation through cohomological transgression.
- Symmetry analysis: configurational and (semi-)gauge symmetries, Noether-Poisson realisations and (classical) central extensions, comomenta and rigid-symmetry algebroids, categorification of symmetries.
- Orbital field dynamics and non-linear realisations of internal and spacetime symmetries. The Ivanov-Ogievietskii (aka inverse Higgs) mechanism. Constructions in the invariant de Rham cohomology, gerbe objects in the category of groups, Nieuwenhuizen's FDA techniques and the rise of Stasheff's L∞-structures via the Baez-Crans correspondence).
- The universal gauge principle and gauge anomalies for symmetries modelled on group actions:
- the standard formulation (association) and the underlying universal mixing construction of Cartan and Borel;
- the Lie groupoid behind the standard formulation and its Higgs module — a MacKenzie-Moerdijk-Mrčun principal groupoid bundle of the Higgs model;
- one Lie groupoid to rule them all — the Atiyah gauge groupoid and the associated short exact sequence of Lie groupoids;
- the Kobayashi-Nomizu induction scheme for associated connections and covariant derivatives, the minimal-coupling recipe for tensorial couplings, descent to configurational orbispaces;
- equivariant-cohomology models and their geometrisations for simplicial couplings, Dirac anomalies in Courant algebroids for symmetries under gauging;
- the gauge defect, twisted sectors and the ensuing simplicial field theory with defects.
- Groupoidal symmetries and their gauging (a report from the frontline):
- the special rôle of bisections and their relation to the tangent Lie algebroid;
- circumnavigating Fréchet: principaloid bundles and their foliated connections;
- the inextricable entwinement of groupoidal matter and radiation in the augmented Atiyah short exact sequence for the groupoidal gauge symmetry;
- the universal gauge principle for tensorial and simplicial field theories;
- the curved Yang-Mills-Higgs theory;
- Q-bundles and the Poisson-σ-model*.
- Some advanced gauge field theory:
- the Anderson-Brout-Englert-Higgs-Guralnik-Hagen-Kibble-... mechanism;
- orbital field dynamics and non-linear realisations of internal and spacetime symmetries, the Ivanov-Ogievietskii (aka inverse Higgs) mechanism, constructions in the invariant de Rham cohomology, gerbe objects in the category of groups, Nieuwenhuizen's FDA techniques and the rise of Stasheff's L∞-structures via the Baez-Crans correspondence;
- standard gauge fields vs gerbe-module connections;
- bi-chiral Kač-Moody symmetries in the Wess-Zumino-Novikov-Witten-Gawędzki model of the two-dimensional Rational Conformal Field Theory*;
- topological gauge field theory — a case study of the Chern-Simons theory in three dimensions in the presence of Wilson lines, of its reduction á la Alekseev and Malkin and of... its intricate relation to the WZNWG model (a hands-on example of `holography').*
- Field theories with the statistical gradation:
- rudiments of supergeometry with supersymmetry (Z/2Z-graded manifolds, super-Harish-Chandra pairs, super-Cartan calculus and Lie-supergroup actions);
- a recapitulation of the theory of spinor bundles with spin connections;
- Freed's inner-Hom superfield theories and their (quasi-)supersymmetry;
- super-σ-models and geometrisations in the Cartan-Eilenberg cohomology of Lie supergroups — supergerbes.*
- Dualities:
- the (pre)symplectic description;
- the defect-duality correspondence;
- useful instantiations: T-duality via gauging of toroidal actions and the ensuing field-bundle topology change, the Hughes-Polchinski duality, S-duality in a weakly abelian gauge field theory*, a sector-restricted duality between the 2d WZNWG RCFT and the 3d CS TGFT — a first step towards functorial quantisation*, and more*...
*Time permitting. ;)
Main fields of studies for MISMaP
physics
Mode
Course coordinators
Learning outcomes
- An in-depth understanding of the (categorified) symmetry principle for Lie-groupoidal symmetries — both rigid and gauged — in the field theory.
- An appreciation of the rôle of spacetime topology in the definition of the field theory, and a working knowledge of a systematic higher-geometric construction of prequantisable field theories with non-tensorial topological couplings.
- A close encounter with field theories with defects.
- An introduction to the mapping of the space of field theories by (categorified) dualities.
- A glimpse into super field theory in its functorial formulation.
Assessment criteria
Evaluation of a discussion to be held during an oral exam resp. of a written report to be submitted upon completion of a self-study project.
Additional information
Additional information (registration calendar, class conductors, localization and schedules of classes), might be available in the USOSweb system: