Higher categories of push-pull spans, II: Matrix factorizations
Pith reviewed 2026-05-23 21:22 UTC · model grok-4.3
The pith
A functor connects the 2-category of matrix factorizations for affine Rozansky-Witten models to the homotopy 2-category of the (∞,3)-category 𝒞RW, allowing calculation of the associated TFTs.
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
Core claim
The central claim is that there exists a functor from the 2-category of matrix factorizations associated to affine Rozansky-Witten models into the homotopy 2-category of 𝒞RW, and that the topological field theories associated to these models can be calculated by passing through this functor.
What carries the argument
The functor from the 2-category of matrix factorizations to the homotopy 2-category of 𝒞RW, which transfers the algebraic data into the higher-categorical setting.
If this is right
- The topological field theories of the affine models are obtained by applying the functor and then evaluating the resulting objects in 𝒞RW.
- The symmetric monoidal structure on 𝒞RW induces a corresponding structure on the images of the matrix factorizations.
- This supplies an explicit approximation, in the affine case, to the 3-category of Kapustin and Rozansky.
Where Pith is reading between the lines
- The functor might serve as a template for defining similar maps from other algebraic models of field theories into higher categories.
- If the functor preserves additional structure, it could be used to extract numerical invariants of three-manifolds directly from matrix factorizations.
Load-bearing premise
The (∞,3)-category 𝒞RW constructed in the companion paper must possess the symmetric monoidal and homotopy properties needed for the functor to land in its homotopy 2-category.
What would settle it
A concrete affine matrix factorization whose image under the functor fails to respect the composition or monoidal product in the homotopy 2-category of 𝒞RW would show the claimed functor does not exist.
read the original abstract
This is the second part of a project aimed at formalizing Rozansky-Witten models in the functorial field theory framework. In the first part we constructed a symmetric monoidal $(\infty, 3)$-category $\mathscr{CRW}$ of commutative Rozansky-Witten models with the goal of approximating the $3$-category of Kapustin and Rozansky. In this paper we extend work of Brunner, Carqueville, Fragkos, and Roggenkamp on the affine Rozansky-Witten models: we exhibit a functor connecting their $2$-category of matrix factorizations with the homotopy $2$-category of $\mathscr{CRW}$, and calculate the associated TFTs.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. This paper is the second part of a project formalizing Rozansky-Witten models in the functorial field theory framework. Building on the symmetric monoidal (∞,3)-category 𝒞RW from the companion paper (part I), it exhibits a functor from the 2-category of matrix factorizations (as studied by Brunner–Carqueville–Fragkos–Roggenkamp) to the homotopy 2-category of 𝒞RW and calculates the associated TFTs for affine Rozansky-Witten models.
Significance. If the functor exists and the TFT calculations are valid, the work connects concrete algebraic data from matrix factorizations to a higher-categorical model approximating the Kapustin–Rozansky 3-category. The explicit functor construction and TFT computations are strengths that could support further calculations in this area.
major comments (1)
- [Introduction and main construction] The existence of the functor and the TFT calculations rest on the symmetric monoidal structure and homotopy 2-category of 𝒞RW as constructed in part I. The manuscript supplies neither an independent definition of 𝒞RW nor a verification that the required properties survive passage to the homotopy 2-category (Introduction and main construction sections). This assumption is load-bearing for the central claim.
minor comments (1)
- [Abstract] The abstract refers to 'the associated TFTs' without indicating which specific models or invariants are computed; a short clarification would aid readability.
Simulated Author's Rebuttal
We thank the referee for their review. The manuscript is the second part of a project, and we address the concern about reliance on part I below.
read point-by-point responses
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Referee: [Introduction and main construction] The existence of the functor and the TFT calculations rest on the symmetric monoidal structure and homotopy 2-category of 𝒞RW as constructed in part I. The manuscript supplies neither an independent definition of 𝒞RW nor a verification that the required properties survive passage to the homotopy 2-category (Introduction and main construction sections). This assumption is load-bearing for the central claim.
Authors: This paper is the second installment of the project and is explicitly framed as such, with the symmetric monoidal (∞,3)-category 𝒞RW constructed in the companion paper (part I). The homotopy 2-category is the standard 2-truncation of this (∞,3)-category, and the symmetric monoidal structure descends to it by the general theory of symmetric monoidal ∞-categories (as verified in part I, sections 3 and 4). The current work applies these structures to construct the functor and compute the TFTs. To make the dependence fully explicit without duplicating part I, we will add a concise summary paragraph in the introduction of the revised version, recalling the relevant definitions and citing the precise statements from part I on which the functor and TFT calculations rely. revision: partial
Circularity Check
No circularity; new functor constructed atop prior category
full rationale
The central result is the explicit construction of a functor from the 2-category of matrix factorizations (Brunner–Carqueville–Fragkos–Roggenkamp) into the homotopy 2-category of the symmetric monoidal (∞,3)-category 𝒞RW, together with the associated TFT calculations. 𝒞RW itself is taken from the companion paper (part I), but the present text supplies an independent mapping and does not redefine any quantity in terms of the functor or TFTs it claims to produce. No equation, definition, or step reduces the claimed functor or TFTs to the inputs by construction, nor does any self-citation serve as the sole justification for a uniqueness or ansatz that would force the result. This is ordinary dependence on prior work rather than circularity.
Axiom & Free-Parameter Ledger
axioms (1)
- domain assumption Existence and symmetric monoidal structure of the (∞,3)-category 𝒞RW constructed in part I.
Reference graph
Works this paper leans on
-
[1]
T runcated affine R ozansky-- W itten models as extended defect TQFT s
Ilka Brunner, Nils Carqueville, Pantelis Fragkos, and Daniel Roggenkamp. T runcated affine R ozansky-- W itten models as extended defect TQFT s. arXiv:2307.06284 https://arxiv.org/abs/2307.06284, 2023. To appear in Comm. Math. Phys
-
[2]
Truncated affine R ozansky- W itten models as extended TQFT s
Ilka Brunner, Nils Carqueville, and Daniel Roggenkamp. Truncated affine R ozansky- W itten models as extended TQFT s. Comm. Math. Phys. , 400(1):371--415, 2023
work page 2023
-
[3]
Lagrangian structures on mapping stacks and semi-classical TFT s
Damien Calaque. Lagrangian structures on mapping stacks and semi-classical TFT s. In Stacks and categories in geometry, topology, and algebra , volume 643 of Contemp. Math. , pages 1--23. Amer. Math. Soc., Providence, RI, 2015
work page 2015
-
[4]
Shifted cotangent stacks are shifted symplectic
Damien Calaque. Shifted cotangent stacks are shifted symplectic. Annales de la Facult\'e des sciences de Toulouse : Math\'ematiques , Ser. 6, 28(1):67--90, 2019
work page 2019
-
[5]
The AKSZ construction in derived algebraic geometry as an extended topological field theory
Damien Calaque, Rune Haugseng, and Claudia Scheimbauer. The AKSZ construction in derived algebraic geometry as an extended topological field theory. arXiv:2108.02473 https://arxiv.org/abs/2108.02473, 2022. To appear in Memoirs of the AMS
-
[6]
Adjunctions and defects in L andau- G inzburg models
Nils Carqueville and Daniel Murfet. Adjunctions and defects in L andau- G inzburg models. Adv. Math. , 289:480--566, 2016
work page 2016
-
[7]
Extending L andau- G inzburg models to the point
Nils Carqueville and Flavio Montiel Montoya. Extending L andau- G inzburg models to the point. Comm. Math. Phys. , 379(3):955--977, 2020
work page 2020
-
[8]
Iterated spans and classical topological field theories
Rune Haugseng. Iterated spans and classical topological field theories. Math. Z. , 289(3-4):1427--1488, 2018
work page 2018
-
[9]
The S erre automorphism via homotopy actions and the cobordism hypothesis for oriented manifolds
Jan Hesse and Alessandro Valentino. The S erre automorphism via homotopy actions and the cobordism hypothesis for oriented manifolds. Cah. Topol. G\'eom. Diff\'er. Cat\'eg. , 60(2):194--236, 2019
work page 2019
-
[10]
Matrix factorizations and link homology
Mikhail Khovanov and Lev Rozansky. Matrix factorizations and link homology. Fund. Math. , 199(1):1--91, 2008
work page 2008
-
[11]
Three-dimensional topological field theory and symplectic algebraic geometry II
Anton Kapustin and Lev Rozansky. Three-dimensional topological field theory and symplectic algebraic geometry II . Commun. Number Theory Phys. , 4(3):463--549, 2010
work page 2010
-
[12]
Three-dimensional topological field theory and symplectic algebraic geometry
Anton Kapustin, Lev Rozansky, and Natalia Saulina. Three-dimensional topological field theory and symplectic algebraic geometry. I . Nuclear Phys. B , 816(3):295--355, 2009
work page 2009
-
[13]
Jacob Lurie. H igher A lgebra . 2017. Available on the author's website https://www.math.ias.edu/ lurie/papers/HA.pdf
work page 2017
-
[14]
The cut operation on matrix factorisations
Daniel Murfet. The cut operation on matrix factorisations. J. Pure Appl. Algebra , 222(7):1911--1955, 2018
work page 1911
-
[15]
Tony Pantev, Bertrand To\" e n, Michel Vaqui\' e , and Gabriele Vezzosi. Shifted symplectic structures. Publ. Math. Inst. Hautes \' E tudes Sci. , 117:271--328, 2013
work page 2013
-
[16]
H igher categories of push-pull spans, I : C onstruction and applications
Lorenzo Riva. H igher categories of push-pull spans, I : C onstruction and applications. arXiv:2404.14597 https://arxiv.org/abs/2404.14597, 2024
-
[17]
Homotopy bicategories of complete 2-fold segal spaces, 2023
Jack Rom\"o. Homotopy bicategories of complete 2-fold segal spaces, 2023. arXiv:2311.11983 https://arxiv.org/abs/2311.11983, 2023
-
[18]
L. Rozansky and E. Witten. Hyper- K \"ahler geometry and invariants of three-manifolds. Selecta Math. (N.S.) , 3(3):401--458, 1997
work page 1997
discussion (0)
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