arXiv subjects

Constantin Teleman

Publications and source records attributed to Constantin Teleman.

At least 19 recordsLinked to original sources

arXiv2026

The role of p_1-structures in 3-dimensional Chern-Simons theories

Our recent paper~\cite{FST} with Claudia Scheimbauer uses the cobordism hypothesis to construct fully local Chern-Simons theories. Here we expose some physics motivations: Yang-Mills plus Chern-Simons in the bosonic case and the free Majorana-Weyl spinor field in the fermionic case. We also give expositions of tangential structures and invertible field theories, in particular the 'gravitational Chern-Simons theory' used by Witten to obtain topological field theories from the physical theories.

hep-th↗

arXiv2026

Fully local Reshetikhin-Turaev theories

Completing an arc of research initiated by Reshetikhin--Turaev and Witten, we construct fully local 3-dimensional topological field theories from non-degenerate braided fusion categories. We do so by defining a symmetric tensor enhancement $\mathrm{E}\mathbb{F}$ with full duals of the 3-category $\mathbb{F}$ of fusion categories, in which every Reshetikhin--Turaev theory has a point generator. This $\mathrm{E}\mathbb{F}$ is a direct sum of invertible $\mathbb{F}$-modules, indexed by a $\mu_6$-extension of the Witt group of non-degenerate braided fusion categories. Similarly, we enhance the 3-category $S\mathbb{F}$ of fusion super-categories to a symmetric tensor 3-category $\mathrm{E} S\mathbb{F}$ with full duals, which is a sum of invertible $S\mathbb{F}$-modules, indexed by a $\mu_{24}$-extension of the super-Witt group. The unit spectrum of $\mathrm{E}S\mathbb{F}$ is the connective cover of the Pontrjagin dual of $\mathbb{S}^{-3}$. We discuss tangential structures and central charges of the resulting TQFTs. We establish Spin-invariance of fusion super-categories, and relate SO-invariance structures to modular and spherical structures, confirming some conjectures from arXiv:1312.7188.

math.QA↗

arXiv2025

Discrete quantum systems from topological field theory

We introduce a technique to construct gapped lattice models using defects in topological field theory. We illustrate with 2+1 dimensional models, for example Chern-Simons theories. These models are local, though the state space is not necessarily a tensor product of vector spaces over the complex numbers. The Hamiltonian is a sum of commuting projections. We also give a topological field theory construction of Levin-Wen models.

hep-th↗

arXiv2024

Integral Kirwan Surjectivity

We refine Kirwan's surjectivity and formality theorems for a Hamiltonian G-action on a compact symplectic manifold M. For a regular value of the moment map, we show that the Kirwan map is surjective and additively split after inverting the orders of stabilizers in the reduction. In particular, for a free quotient, it is surjective integrally. We generalize this to a splitting of MU-module spectra. We also give a stable version of Kirwan's equivariant formality theorem. The novel idea is to exploit the Atiyah-Bott argument in Morava K-theory, then return to bordism and cohomology.

math.SG↗

arXiv2024

Gapped theories have torsion anomalies

We prove special cases of a general conjecture: If an invertible field theory admits a projectively topological boundary theory, then it has finite order in the abelian group of invertible field theories. One can substitute `gapped' for `projectively topological'. Our proofs use evaluations of a field theory in parametrized families.

hep-th↗

arXiv2024

Quantization commutes with reduction again: the quantum GIT conjecture I

For a compact monotone symplectic manifold $X$ with Hamiltonian action of a compact Lie group $G$ and smooth symplectic reduction, we relate its gauged $2$-dimensional $A$-model to the $A$-model of $X/\!/G$. This (long conjectured) result is parallel to the ($B$-model!) \emph{quantization commutes with reduction} theorem of Guillemin and Sternberg in quantum mechanics. Here, we spell out some of the precise statements, and outline the proof of equality for the spaces of states (quantum cohomology). We also indicate the way to some related results in the non-monotone case. Additional Floer theory details will be included in a follow-up paper.

math.SG↗

arXiv2024

The Odd Fermion

In this short note we use the geometric approach to (topological) field theory to address the question: Does an odd number of quantum mechanical fermions make sense?

hep-th↗

arXiv2022

Topological symmetry in quantum field theory

We introduce a framework for internal topological symmetries in quantum field theory, including "noninvertible symmetries" and "categorical symmetries". This leads to a calculus of topological defects which takes full advantage of well-developed theorems and techniques in topological field theory. Our discussion focuses on finite symmetries, and we give indications for a generalization to other symmetries. We treat quotients and quotient defects (often called "gauging" and "condensation defects"), finite electromagnetic duality, and duality defects, among other topics. We include an appendix on finite homotopy theories, which are often used to encode finite symmetries and for which computations can be carried out using methods of algebraic topology. Throughout we emphasize exposition and examples over a detailed technical treatment.

hep-th↗

arXiv2022

Coulomb branches for quaternionic representations

I describe the \emph{Chiral rings} $R_{3,4}$ for $3$D, $N=4$ supersymmetric $G$-gauge theory and matter fields in quaternionic representations $E$: first, by a topological tweak of the construction of arxiv:1601.03586, and second, more explicitly, by Weyl group descent from the maximal torus. A topological obstruction is $w_4(E)$ modulo squares, for $R_3$; a secondary obstruction, from $\eta\cdot E$, may appear for $R_4$. Flatness over the Toda bases allows their calculation by reduction to $\mathrm{SU}_2$. For some representations, an Abelianization formula describes the $R$ in terms of the maximal torus and the Weyl group. This provides an alternative to a recent attempt arxiv:2201.09475.

math.AT↗

arXiv2020

Gapped boundary theories in three dimensions

We prove a theorem in 3-dimensional topological field theory: a Reshetikhin-Turaev theory admits a nonzero boundary theory iff it is a Turaev-Viro theory. The proof immediately implies a characterization of fusion categories in terms of dualizability. The main theorem applies to physics, where it implies an obstruction to a gapped 3-dimensional quantum system admitting a gapped boundary theory. Appendices on bordism multicategories and on internal duals may be of independent interest.; v2 extensive revision: added theorem on dualizable 2-categories, material on natural transformations, reworked theorems and several proofs, and more.

math.QA↗

arXiv2018

Topological dualities in the Ising model

We relate two classical dualities in low-dimensional quantum field theory: Kramers-Wannier duality of the Ising and related lattice models in $2$ dimensions, with electromagnetic duality for finite gauge theories in $3$ dimensions. The relation is mediated by the notion of boundary field theory: Ising models are boundary theories for pure gauge theory in one dimension higher. Thus the Ising order/disorder operators are endpoints of Wilson/'t Hooft defects of gauge theory. Symmetry breaking on low-energy states reflects the multiplicity of topological boundary states. In the process we describe lattice theories as (extended) topological field theories with boundaries and domain walls. This allows us to generalize the duality to non-abelian groups; finite, semi-simple Hopf algebras; and, in a different direction, to finite homotopy theories in arbitrary dimension.

math.AT↗

arXiv2018

The role of Coulomb branches in 2D gauge theory

I give a simple construction of certain Coulomb branches $C_{3,4}(G;E)$ of gauge theory in 3 and 4 dimensions defined by Nakajima et al. for a compact Lie group $G$ and a polarisable quaternionic representation $E$. The manifolds $C(G; 0)$ are abelian group schemes (over the bases of regular adjoint $G_c$-orbits, respectively conjugacy classes), and $C(G;E)$ is glued together from two copies of $C(G;0)$ shifted by a rational Lagrangian section $\varepsilon_V$, the Euler class of the index bundle of a polarisation $V$ of $E$. Extending the interpretation of $C_3(G;0)$ as "classifying space" for topological 2D gauge theories, I characterise functions on $C_3(G;E)$ as operators on the equivariant quantum cohomologies of $M\times V$, for all compact symplectic $G$-manifolds $M$. The non-commutative version has an analogous description in terms of the $\Gamma$-function of $V$, appearing to play the role of Fourier transformed J-function of the gauged linear Sigma-model $V/G$.

math.AG↗

arXiv2016

Matrix Factorisation of Morse-Bott functions

For a function $W\in \mathbb{C}[X]$ on a smooth algebraic variety $X$ with Morse-Bott critical locus $Y\subset X$, Kapustin, Rozansky and Saulina suggest that the associated matrix factorisation category $\mathrm{MF}(X;W)$ should be equivalent to the differential graded category of $2$-periodic coherent complexes on $Y$ (with a topological twist from the normal bundle of $Y$). I confirm their conjecture in the special case when the first neighbourhood of $Y$ in $X$ is split, and establish the corrected general statement. The answer involves the full Gerstenhaber structure on Hochschild cochains. This note was inspired by the failure of the conjecture, observed by Pomerleano and Preygel, when $X$ is a general one-parameter deformation of a $K3$ surface $Y$.

math.AG↗

arXiv2014

Dirac Families for Loop Groups as Matrix Factorizations

We identify the category of integrable lowest-weight representations of the loop group LG of a compact Lie group G with the linear category of twisted, conjugation-equivariant curved Fredholm complexes on the group G: namely, the twisted, equivariant matrix factorizations of a super-potential built from the loop rotation action on LG. This lifts the isomorphism of K-groups of [FHT1,2, 3] to an equivalence of categories. The construction uses families of Dirac operators.

math.AT↗

arXiv2014

Gauge theory and mirror symmetry

Outlined in this paper is a description of \emph{equivariance} in the world of 2-dimensional extended topological quantum field theories, under a topological action of compactLie groups. In physics language, I am gauging the theories --- coupling them to a principal bundle on the surface world-sheet. I describe the data needed to gauge the theory, as well as the computation of the gauged theory, the result of integrating over all bundles. The relevant theories are A-models, such as arise from the Gromov-Witten theory of a symplectic manifold with Hamiltonian group action, and the mathematical description starts with a group action on the generating category (the Fukaya category, in this example) which is factored through the topology of the group. Their mirror description involves holomorphic symplectic manifolds and Lagrangians related to the Langlands dual group. An application recovers the complex mirrors of flag varieties proposed by Rietsch.

math-ph↗

arXiv2014

Relative quantum field theory

We highlight the general notion of a relative quantum field theory, which occurs in several contexts. One is in gauge theory based on a compact Lie algebra, rather than a compact Lie group. This is relevant to the maximal superconformal theory in six dimensions.

hep-th↗

arXiv2013

Geometric Langlands Correspondence Near Opers

We extend the categorical geometric Langlands correspondence from the locus of opers in the stack of de Rham local systems on a smooth projective algebraic curve to the formal neighborhood of opers (for any semi-simple complex algebraic group).

math.AG↗

arXiv2012

Loop Groups and Twisted K-Theory II

This is the second in a series of papers investigating the relationship between the twisted equivariant K-theory of a compact Lie group G and the "Verlinde ring" of its loop group. We introduce the Dirac family of Fredholm operators associated to a positive energy representation of a loop group. It determines a map from isomorphism classes of representations to twisted K-theory, which we prove is an isomorphism if $G$ is connected with torsion-free fundamental group. We also introduce a Dirac family for finite dimensional representations of compact Lie groups; it is closely related to both the Kirillov correspondence and the equivariant Thom isomorphism. In Part III (math.AT/0312155) we extend the proof of our main theorem to arbitrary compact Lie groups G and provide supplements in various directions. In Part I (arXiv:0711.1906) we develop twisted equivariant K-theory and carry out some of the computations needed here. We refer to the announcements math.AT/0312155 and math.AT/0206237 for further expository material and motivation.

math.AT↗