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REVIEW 2 major objections 3 minor 68 references

Pontryagin-Weiss classes and a rational decomposition of spaces of homeomorphisms

T0 review · 2 major / 3 minor · reviewed 2026-08-16 · deepseek-v4-flash

Pith's one-line read For every d≥6 and k≥1, a Euclidean R^d-bundle over the 4k-sphere realizes the k-th rational Pontryagin class.

desk verdict A substantial, honest paper that resolves Weiss's sphere-detection question for Euclidean bundles in dimensions d>=6; the main theorem sits on imported embedding-calculus estimates, so it deserves refereeing rather than desk rejection. read the letter →

arxiv 2504.20265 v2 pith:LT2XNPZO submitted 2025-04-28 math.AT math.GT

classification math.ATmath.GT MSC 55R4057R2057S0555P62
keywords topologicalPontryaginclassesEuclideanbundleshomeomorphismgroupsrationalhomotopypullbackdecompositionembeddingcalculusstabilisationmapcharacteristicE_doperad
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The reading

The paper establishes that rational Pontryagin classes of Euclidean fibre bundles do not vanish in fixed rank: for all $d \ge 6$ and $k \ge 1$, there is a fibre bundle over $S^{4k}$ with fibre $\mathbb{R}^d$ whose $k$-th rational Pontryagin class is nonzero. Equivalently, the stabilisation map $BTop(d) \to BTop$ from homeomorphisms of $\mathbb{R}^d$ to stable homeomorphisms is rationally surjective on homotopy groups after looping, a property that the previously known injectivity on rational cohomology does not by itself supply. The proof works by constructing a rational homotopy pullback decomposition for classifying spaces of homeomorphism groups, which lets one change the vertical tangent bundle of a fibre bundle without changing the underlying fibration. A reader should care because this supplies a new construction method for topological bundles with prescribed characteristic classes and yields infinite families of previously undetected rational homotopy groups of disc diffeomorphism spaces.

What carries the argument

The central object is a rational homotopy pullback square completing the sequence $$BHomeo^\theta_\partial(M;\ell_{1/2\partial})^{f\mathbb{Q}} \to BAut^\theta_\partial(TM;\ell_{1/2\partial})^{f\mathbb{Q}} \to BAut_\partial(M)_{\ell_{1/2\partial}}$$ for smoothable 2-connected compact $d$-manifolds with $d \ge 5$, 2-connected boundary, and an oriented tangential structure through $BSTop(d-2)$ after rationalisation. The square lets the vertical tangent bundle of a topological $M$-bundle be varied independently of the underlying fibration. Its construction rests on Theorem G: the twice-iterated stabilisation map $BSAut(E_{d-2,\mathbb{Q}}) \to BSAut(E_{d,\mathbb{Q}})$ is nullhomotopic, where $E_{d,\mathbb{Q}}$ is the rationalised little-$d$-discs operad and $SAut$ is the kernel of the action on the top homology of binary operations; this nullhomotopy makes the rationalised tangential-structure classifying map factor through a contractible piece.

What would settle it

A concrete falsifier would be to compute, for $d=6$ and $k=3$, the evaluation of $p_3$ on the Hurewicz image of $\pi_{12}(BSTop(6))$ using the paper's pullback square and find it zero, or to exhibit any $d \ge 6$ and $k \ge 1$ for which the double-stabilisation map $BSAut(E_{d-2,\mathbb{Q}}) \to BSAut(E_{d,\mathbb{Q}})$ is not nullhomotopic, which would break Theorem G and hence the decomposition.

Watch

Extended reading notes

Core claim

The paper proves that for every $d \ge 6$ and $k \ge 1$, the $k$-th rational Pontryagin class $p_k \in H^{4k}(BSTop(d); \mathbb{Q})$ evaluates nontrivially on the Hurewicz image of $\pi_{4k}(BSTop(d))$, equivalently that some $\mathbb{R}^d$-bundle over $S^{4k}$ has nonzero $p_k$, and that the stabilisation map $BTop(d) \to BTop$ admits a rational section after looping. The engine is a rational homotopy pullback decomposition for classifying spaces of homeomorphism groups with tangential structures (Theorem F, proved as Theorem 5.1), obtained by combining topological and particle embedding calculus convergence with a new nullhomotopy of the twice-iterated stabilisation map for automorphisms of the rational $E_d$-operad (Theorem G). From the same decomposition the paper also derives a rational Burghelea–Lashof splitting without Postnikov truncation and a method for detecting tautological classes of topological manifold bundles.

Load-bearing premise

The proof depends on unproved technical estimates about how well spaces of embeddings of a manifold are approximated by a sequence of simpler spaces; if those estimates fail, the central pullback decomposition and the main theorems collapse.

Editorial extensions

If this is right

  • For every $d \ge 6$ there is a rational section, after looping, of the stabilisation map $BTop(d) \to BTop$, so the latter is surjective on rational homotopy groups.
  • The disc diffeomorphism space $BDiff_\partial(D^d)$ for $d \ge 6$ has infinitely many nontrivial rational homotopy groups, many outside previously computed ranges and in degrees different from configuration-space-integral classes.
  • A rational Burghelea–Lashof splitting holds without Postnikov truncation for a large class of 2-connected smoothable manifolds, giving topological (not smooth) sections of the forgetful map from fibre-homotopically trivialised fibre bundles to block bundles after looping.
  • For manifolds containing $S^m \times S^{d-m}$ as a connected summand, the tautological classes $\kappa_{p_i p_j}$ are nonzero under explicit degree bounds, and the rational cohomology of the homeomorphism group can grow faster than any polynomial.
  • The pullback decomposition itself gives a general detection principle: to detect a characteristic class of topological $M$-bundles it suffices to detect the corresponding tautological class on a fibrewise rationalised mapping space.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • If the pullback square is as robust as Theorem F suggests, the same mechanism should construct integral rather than rational Pontryagin classes on sphere bundles whenever an integral version of the nullhomotopy input can be supplied.
  • Theorem G's nullhomotopy of the double stabilisation of $SAut(E_{d,\mathbb{Q}})$ may imply a stronger, essentially formal control over the rational homotopy type of automorphism spaces of the $E_d$-operad; the paper deliberately avoids graph-complex methods, leaving this as a natural check.
  • The $T_\infty$-boundary discussion points to a new invariant of a manifold's interior recoverable from embedding calculus; testing it on homology spheres with nontrivial fundamental group would map out exactly when boundaries can be recovered from interiors.
  • The same decomposition could be combined with other tangential structures to detect unstable classes of $BTop(d)$ beyond Pontryagin classes, such as products of classes or classes pulled back from the identity component.
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Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

2 major / 3 minor

Summary. The paper constructs, for smoothable compact d-manifolds with 2-connected interior and boundary, a rational homotopy pullback decomposition for classifying spaces of homeomorphisms and self-embeddings (Theorem F, refined in Theorem 5.1). It applies this decomposition to prove that for d≥6 and k≥1 the kth rational Pontryagin class p_k is nonzero on a topological R^d-bundle over S^{4k} (Theorem A / Theorem 6.8), that the stabilisation map BTop(d)→BTop has a rational section after looping (Corollary B), that BDiff_∂(D^d) has infinitely many nontrivial rational homotopy groups (Corollary C), and that a rational Burghelea–Lashof splitting holds without Postnikov truncation under mild hypotheses (Theorem D/Theorem 6.10). A further application detects certain products of tautological Pontryagin classes (Theorem E). The proof combines a nullhomotopy result for the twice-iterated stabilisation map on SAut(E_{d,Q}) (Theorem G), embedding-calculus estimates imported from the authors' prior work [KK24c], and a new boundary-recovery statement in embedding calculus (Theorem 4.1).

Significance. If the central theorem is correct, the paper solves a problem left open by Weiss and strengthens the Galatius–Randal-Williams stable result in the homotopical direction: it produces sphere bundles with nonzero rational Pontryagin classes in all degrees for d≥6, without proving (and not needing) the corresponding homology surjectivity. The method is novel: the pullback decomposition gives a mechanism to modify vertical tangent bundles of bundles while keeping the underlying fibration fixed, which is the engine behind Theorems A, D, and E. The paper is unusually explicit about its technical assumptions and limitations: Remarks 5.2 and 6.7 flag the fibrewise-nilpotency issue, Remark 4.2(ii) flags the dependence on convergence of topological embedding calculus, and the appendices contain substantial independent material on tensor products of truncated and rational pro-operads. The proof of Theorem G is independent of the Fresse–Willwacher graph-complex route, which is a genuine contribution. The main reservation is that several load-bearing connectivity and pullback statements are cited from the authors' own [KK24c] rather than proved or precisely restated here.

major comments (2)
  1. [§4.3–§4.4, §5.1–§5.2 (Lemmas 4.7, 4.8, 5.3)] The pullback decomposition in Theorem 5.1 (and hence Theorem F and its applications A, D, E) rests on imported embedding-calculus estimates from [KK24c] that are not reproved in this paper. Specifically, Lemma 4.7(ii) cites [KK24c, Theorem 6.3 and Remark 6.11] for the (k−d+3)-connectivity of ∂^h W → ∂^h_{≤k} W; Lemma 4.8 cites [KK24c, Section 5.7] for the pullback square relating topological and particle embedding calculus; and Lemma 5.3 again uses [KK24c, Theorem 6.3 and Remark 6.11]. The dashed filler in Theorem 4.1, and with it the pullback square (34) in Proposition 5.5, would fail if the cited connectivity bound were off by one or if the pullback in [KK24c, §5.7] had a component/basepoint subtlety. Since these statements are the single most load-bearing external input, the authors should either prove them (perhaps in an appendix) or restate them as explicit, precisely formulated hypotheses of Theorems 5.1 and 6.8, so that the reader can verify the dependency.
  2. [§5.2, Remark 5.2, Proposition 5.5] The paper acknowledges in Remark 5.2 that fibrewise nilpotency of BEmb^θ_{∂v}(M;ℓ_v)^× is not established, and argues it is unnecessary. However, the proof of Proposition 5.5 applies Lemma 2.1 to the square obtained by taking fibres to basepoints, and the reader must infer that the bottom row of that fibre square is the map on diagonal fibres of (35) and that it is 1-connected and nilpotent. This is plausible, but the argument is currently compressed into one sentence. Please expand this step to make explicit why Lemma 2.1 applies without any nilpotency assumption on the BEmb-term, and reconcile this with the statement in Remark 5.2(i) that the missing nilpotency can be proved by future work.
minor comments (3)
  1. [§3.2, Proposition 3.8] In the proof of Proposition 3.8, the case SAut≤2(E_{d,Q}) invokes 'the final part of Lemma 3.7(v)', but Lemma 3.7(v) carries an exception for k=2 and degrees i=j=d−1. The exception appears not to contribute to the Bousfield–Kan spectral sequence for π_i of the mapping space because the relevant entry is H^0(S^{d-1}_Q; π_{d-1}). Please add a sentence confirming that the exceptional degree cannot occur, to remove any ambiguity.
  2. [§6.3, Proof of Theorem 6.8] The reduction to d=6 and k≥3 is stated correctly, but for k=1,2 the text says p_k evaluates nontrivially on π_{4k}(BSO(6)) without giving a reference. A short citation or one-line argument would improve readability.
  3. [§1, Theorem D / §6.4, Theorem 6.10] The dimension hypothesis in Theorem D is d≥13, while Theorem 6.10 states a sharper result with d≥8 and additional conditions. It would help the reader to see this relationship stated explicitly in the introduction, since the current phrasing makes Theorem D appear to be a direct corollary rather than a special case of a sharper theorem.

Circularity Check

0 steps flagged · score 0.0 of 10

No circularity: the central theorems rest on prior embedding-calculus results, but those are parameter-free external inputs rather than restatements of the target claims.

full rationale

The paper's main derivation chain is: Theorem A follows from Theorem 6.8; Theorem 6.8 uses Theorem F and the pullback decomposition of Section 5; Theorem F/Theorem 5.1 uses Theorem 4.1; and Theorem 4.1 uses Lemmas 4.7 and 4.8. The only self-cited inputs at these load-bearing steps are results from the authors' prior work [KK24c] on embedding calculus: Lemma 4.7(ii) cites [KK24c, Theorem 6.3 and Remark 6.11] for connectivity estimates, and Lemma 4.8 cites [KK24c, Section 5.7] for a pullback square relating topological and particle embedding calculus. These are parameter-free theorems with stated hypotheses (smoothable manifolds, d >= 5, tangential 2-type conditions) that do not include the target conclusions about Pontryagin classes or the pullback decomposition itself. Under the stated review rules, a parameter-free cited theorem with assumptions that do not include the target result counts as independent support, so this self-citation does not constitute circularity. Similarly, the use of [KK24a, Theorems 7.9-7.10] in Proposition 5.5 is a computational input about automorphism spaces of rational E_d-operads, not a hidden version of the claimed nontriviality of Pontryagin classes. The paper's own Theorem G is proved internally in Section 3, with a proof independent of the main pullback decomposition and not derived from the target result. The applications, including the proof of Theorem 6.8, involve a genuine construction using Galatius-Randal-Williams stable moduli space results and the Pontryagin-Thom map; no fitted parameters are introduced and no quantity called a prediction is obtained by construction from the data that define it. The paper explicitly flags in Remark 5.2 that fibrewise nilpotency of one space is not established but argues it is unnecessary for the applications; this is a technical limitation or correctness risk, not a circular step, because the argument does not assume the conclusion it aims to prove. Overall, no equation or proof step reduces to its own input by definition, and no central claim is a renamed input or a forced consequence of a self-citation chain. Therefore the circularity score is 0.

Assumptions & free parameters 0 free parameters · 8 assumptions · 0 invented entities

The paper's central claim is parameter-free: no constants are fitted to data. The proof rests on standard foundations (∞-categories, Bousfield-Kan rationalisation), on external theorems (Drinfel'd, GRW17, BB18, topological Poincaré conjecture), and on the authors' own embedding calculus results from [KK24c] and [KK24a]. The latter are self-citations used as black boxes, which raises the circularity-burden score slightly but does not amount to circular reasoning.

assumptions (8)
  • standard math The ∞-categorical framework of Lurie (quasi-categories, ∞-operads) is taken as foundational throughout.
    Invoked in the Convention paragraph of Section 2 and used in all sections; no alternative foundations are supplied.
  • standard math Bousfield-Kan Q-completion is the rationalisation functor with the stated inheritance properties, including Lemma 2.1.
    Section 2.1 defines rationalisation and proves Lemma 2.1, but relies on standard properties of Bousfield-Kan completion from BK72.
  • standard math Dunn-Lurie additivity: E_n ⊗ E_m ≃ E_{n+m} and the map t: BTop(d) → BAut(E_d).
    Sections 2.2.2 and diagram (5); the equivalence is cited to Lurie17 and not reproved.
  • domain assumption Drinfel'd's theorem: the map χ: Aut(E_{2,Q}) → GL(Q) is surjective.
    Theorem 3.3, used to choose Λ with χ(Λ) ≠ ±1 in Proposition 3.4; cited to Drinfel'd and BdBH21, not reproved.
  • domain assumption Topological and particle embedding calculus results of [KK24c], including convergence and connectivity estimates (Theorem 6.3, Remark 6.11) and the pullback square of Section 5.7.
    Used in Lemmas 4.7, 4.8 and equation (32); these are the authors' own prior theorems, cited as black boxes.
  • domain assumption Galatius-Randal-Williams [GRW17, Corollary 1.8]: the parametrised Pontryagin-Thom map induces a cohomology isomorphism in a range growing with genus.
    Used in the proof of Theorem 6.8 to detect κ_{L_k} on BDiff^{θ_sm}_∂(W_{g,1}) for g large.
  • domain assumption Stable homeomorphism theorem and the high-dimensional topological Poincaré conjecture, together with the Alexander trick.
    Used in the proof of Theorem F to identify the identity component of Top(d) with STop(d) and to identify certain acyclic 1-connected manifolds as discs.
  • domain assumption Burklund-Barron [BB18, Corollary 3]: the coefficient of p_1^k in the Hirzebruch L-class L_k is nonzero.
    Used in the proof of Theorem 6.8 to show L_k is nonzero in the cohomology of τ_{>3}BSO(4).

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Pith. "Pith review of Pontryagin-Weiss classes and a rational decomposition of spaces of homeomorphisms." pith.science (2026). https://pith.science/paper/LT2XNPZO

@misc{pith2026250420265,
  author       = {Pith},
  title        = {Pith review of: Pontryagin-Weiss classes and a rational decomposition of spaces of homeomorphisms},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/LT2XNPZO}},
  note         = {Machine review of arXiv:2504.20265}
}
abstract

We construct a rational homotopy pullback decomposition for variants of the classifying space of the group of homeomorphisms for a large class of manifolds. This has various applications, including a rational section of the stabilisation map ${\rm Top}(d)\rightarrow {\rm Top}$ of the space of homeomorphisms of ${\bf R}^d$ for $d\ge 6$, or a new method to construct topological bundles and detect characteristic classes thereof. Some steps in the proofs may be of independent interest, such as the construction of a nullhomotopy of the twice-iterated stabilisation map for the space of orientation-preserving derived automorphisms of the rational $E_d$-operad, results on recovering boundaries of manifolds from the interior in the context of embedding calculus, or a treatment of tensor products of truncated $\infty$-operads.

Figures

Figures reproduced from arXiv: 2504.20265 by the authors.

Figure 1
Figure 1. A bordism 𝑊 : 𝑂 { 𝑄 of manifolds with boundary. A collar is dashed. 4.1. Embeddings. We begin by constructing the dashed filler in (14). To do so, instead of con￾sidering compact manifold triads (𝑀, 𝜕𝑣𝑀, 𝜕ℎ𝑀) as above, we work in the slightly more general setting of compact bordisms 𝑊 : 𝑂 { 𝑄 of manifolds with boundary, i.e. compact manifold triads (𝑊 , 𝜕𝑣𝑊 , 𝜕ℎ𝑊 ) with an ordered decomposition 𝜕 𝑣𝑊 = 𝑂 ⊔ 𝑄 of the v… view at source ↗
Figure 2
Figure 2. The bordism 𝑀𝑐 : 𝜕 𝑣𝑀 { ∅ is obtained by composing the left-hand bordism 𝜕 𝑣𝑀 × 𝐼 : 𝜕 𝑣𝑀 { 𝜕 𝑣𝑀 with the right-hand bordism 𝑀 : 𝜕 𝑣𝑀 { ∅. Note that, written like this, the action on 𝜕 ℎ𝑊 ⊂ 𝑊 in the arrow category S [1] of the ∞-category of spaces visibly factors through Homeo𝜕 𝑣 (𝑊 ) → Emb𝜕 𝑣 (𝑊 ) × , in a way that is compatible with the a priori action of Emb𝜕 𝑣 (𝑊 ) × on 𝐸𝑊 ≃ 𝑊 . Moreover, this construction is nat… view at source ↗
Figure 3
Figure 3. The inner square of (63). Each dashed box indicates an element in the respective space. The ≃-signs in the dashed boxes indicate paths of operations. The ≃-sign between the two bottom-right dashed boxes indicates the homotopy between the clockwise and counterclockwise composition of maps in the square. Proof of Lemma A.11. We first prove that the natural transformation is an equivalence when O = 𝐸𝑛 and P = 𝐸𝑚 (we wi… view at source ↗

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Works this paper leans on

68 extracted references · 57 canonical work pages

  1. [1]

    Berglund and J

    A. Berglund and J. Bergstr\" o m, Hirzebruch L -polynomials and multiple zeta values , Math. Ann. 372 (2018), no. 1-2, 125--137. 3856808

  2. [2]

    Boavida de Brito and G

    P. Boavida de Brito and G. Horel, On the formality of the little disks operad in positive characteristic, J. Lond. Math. Soc. (2) 104 (2021), no. 2, 634--667. 4311106

  3. [3]

    Boavida de Brito and M

    P. Boavida de Brito and M. Weiss, Spaces of smooth embeddings and configuration categories, J. Topol. 11 (2018), no. 1, 65--143. 3784227

  4. [4]

    Boavida de Brito and M

    P. Boavida de Brito and M. S. Weiss, The configuration category of a product, Proc. Amer. Math. Soc. 146 (2018), no. 10, 4497--4512. 3834674

  5. [5]

    Blanc, W

    D. Blanc, W. G. Dwyer, and P. G. Goerss, The realization space of a -algebra: a moduli problem in algebraic topology , Topology 43 (2004), no. 4, 857--892. 2061210

  6. [6]

    Bustamante, F

    M. Bustamante, F. T. Farrell, and Y. Jiang, On negatively curved bundles with hyperbolic fibers outside the I gusa stable range , Math. Ann. 372 (2018), no. 3-4, 1631--1641. 3880310

  7. [7]

    Barnea, Y

    I. Barnea, Y. Harpaz, and G. Horel, Pro-categories in homotopy theory, Algebr. Geom. Topol. 17 (2017), no. 1, 567--643. 3604386

  8. [8]

    Barkan, R

    S. Barkan, R. Haugseng, and J. Steinebrunner, Envelopes for algebraic patterns, 2022, arXiv:2208.07183, to appear in Algebr. Geom. Topol

Show all 68 references
  1. [9]

    A. K. Bousfield and D. M. Kan, Homotopy limits, completions and localizations, Lecture Notes in Mathematics, Vol. 304, Springer-Verlag, Berlin-New York, 1972. 0365573

  2. [10]

    Burghelea and R

    D. Burghelea and R. Lashof, Geometric transfer and the homotopy type of the automorphism groups of a manifold, Trans. Amer. Math. Soc. 269 (1982), no. 1, 1--38. 637027

  3. [11]

    A. K. Bousfield, Homological localization towers for groups and -modules , Mem. Amer. Math. Soc. 10 (1977), no. 186, vii+68. 447375

  4. [12]

    F. R. Cohen and S. Gitler, On loop spaces of configuration spaces, Trans. Amer. Math. Soc. 354 (2002), no. 5, 1705--1748. 1881013

  5. [13]

    Collins, Configuration spaces and operads, 2019, MSc thesis, Utrecht University

    K.D. Collins, Configuration spaces and operads, 2019, MSc thesis, Utrecht University

  6. [14]

    A. S. Dubey and Y. L. Liu, Unital k -restricted infinity-operads, 2024, arXiv:2407.17444

  7. [15]

    V. G. Drinfel'd, On quasitriangular quasi- H opf algebras and on a group that is closely connected with Gal ( Q / Q ) , Algebra i Analiz 2 (1990), no. 4, 149--181. 1080203

  8. [16]

    F\'elix, S

    Y. F\'elix, S. Halperin, and J.-C. Thomas, Rational homotopy theory, Graduate Texts in Mathematics, vol. 205, Springer-Verlag, New York, 2001. 1802847

  9. [17]

    Fresse, Homotopy of operads and G rothendieck- T eichm\" u ller groups

    B. Fresse, Homotopy of operads and G rothendieck- T eichm\" u ller groups. P art 1 , Mathematical Surveys and Monographs, vol. 217, American Mathematical Society, Providence, RI, 2017, The algebraic theory and its topological background. 3643404

  10. [18]

    Frenck, Sphericity of -classes and positive curvature via block bundles , arXiv:2109.10306

    G. Frenck, Sphericity of -classes and positive curvature via block bundles , arXiv:2109.10306

  11. [19]

    Fiedorowicz and R

    Z. Fiedorowicz and R. M. Vogt, An additivity theorem for the interchange of E_n structures , Adv. Math. 273 (2015), 421--484. 3311768

  12. [20]

    Fresse and T

    B. Fresse and T. Willwacher, Mapping Spaces for DG Hopf Cooperads and Homotopy Automorphisms of the Rationalization of E_n -operads , arXiv:2003.02939

  13. [21]

    Galatius, I

    S. Galatius, I. Grigoriev, and O. Randal-Williams, Tautological rings for high-dimensional manifolds, Compos. Math. 153 (2017), no. 4, 851--866. 3705243

  14. [22]

    Gepner and R

    D. Gepner and R. Haugseng, Enriched -categories via non-symmetric -operads , Adv. Math. 279 (2015), 575--716. 3345192

  15. [23]

    Gepner, R

    D. Gepner, R. Haugseng, and T. Nikolaus, Lax colimits and free fibrations in -categories , Doc. Math. 22 (2017), 1225--1266. 3690268

  16. [24]

    Galatius and O

    S. Galatius and O. Randal-Williams, Homological stability for moduli spaces of high dimensional manifolds. II , Ann. of Math. (2) 186 (2017), no. 1, 127--204. 3665002

  17. [25]

    Reine Angew

    , Algebraic independence of topological P ontryagin classes , J. Reine Angew. Math. 802 (2023), 287--305. 4635347

  18. [26]

    G\"oppl and M

    F. G\"oppl and M. Weiss, A spectral sequence for spaces of maps between operads, Algebr. Geom. Topol. 24 (2024), no. 3, 1655--1690. 4767883

  19. [27]

    W. C. Hsiang and B. Jahren, A note on the homotopy groups of the diffeomorphism groups of spherical space forms, Algebraic K -theory, P art II ( O berwolfach, 1980), Lecture Notes in Math., vol. 967, Springer, Berlin-New York, 1982, pp. 132--145. 689391

  20. [28]

    Heuts and I

    G. Heuts and I. Moerdijk, Simplicial and dendroidal homotopy theory, Ergebnisse der Mathematik und ihrer Grenzgebiete. 3. Folge. A Series of Modern Surveys in Mathematics, vol. 75, Springer, Cham, 2022. 4485749

  21. [29]

    Hinich and I

    V. Hinich and I. Moerdijk, On the equivalence of L urie's -operads and dendroidal -operads , J. Topol. 17 (2024), no. 4, Paper No. e70003, 31. 4822931

  22. [30]

    Horel, Binomial rings and homotopy theory, J

    G. Horel, Binomial rings and homotopy theory, J. Reine Angew. Math. 813 (2024), 283--305. 4780987

  23. [31]

    Hoyois, The \'etale symmetric K \"unneth theorem , Math

    M. Hoyois, The \'etale symmetric K \"unneth theorem , Math. Z. 304 (2023), no. 1, Paper No. 1, 28. 4568994

  24. [32]

    Hilton and J

    P. Hilton and J. Roitberg, Relative epimorphisms and monomorphisms in homotopy theory, Compositio Math. 61 (1987), no. 3, 353--367. 883488

  25. [33]

    D. C. Isaksen, Completions of pro-spaces, Math. Z. 250 (2005), no. 1, 113--143. 2136405

  26. [34]

    P. J. Kahn, A note on topological P ontrjagin classes and the H irzebruch index formula , Illinois J. Math. 16 (1972), 243--256. 292096

  27. [35]

    J. M. Kister, Microbundles are fibre bundles, Ann. of Math. (2) 80 (1964), 190--199. 180986

  28. [36]

    Krannich and A

    M. Krannich and A. Kupers, Weight decompositions and automorphism groups of manifolds, Oberwolfach Report 36/2019 (J. Grodal, M. Hill, and B. Richter, eds.), 2019

  29. [37]

    Pi 12 (2024), Paper No

    , The D isc-structure space , Forum Math. Pi 12 (2024), Paper No. e26. 4838966

  30. [38]

    , Embedding calculus for surfaces, Algebr. Geom. Topol. 24 (2024), no. 2, 981--1018. 4735050

  31. [39]

    , -operadic foundations for embedding calculus, arXiv:2409.10991

  32. [40]

    Krannich, A

    M. Krannich, A. Kupers, and O. Randal-Williams, An H P ^2 -bundle over S^4 with nontrivial A -genus , C. R. Math. Acad. Sci. Paris 359 (2021), 149--154. 4237630

  33. [41]

    Krannich, A homological approach to pseudoisotopy theory

    M. Krannich, A homological approach to pseudoisotopy theory. I , Invent. Math. 227 (2022), no. 3, 1093--1167. 4384194

  34. [42]

    Kupers and O

    A. Kupers and O. Randal-Williams, The cohomology of T orelli groups is algebraic , Forum Math. Sigma 8 (2020), Paper No. e64, 52. 4190064

  35. [43]

    Krannich and O

    M. Krannich and O. Randal-Williams, Diffeomorphisms of discs and the second W eiss derivative of BTop(-) , 2021, arXiv:2109.03500

  36. [44]

    Kupers and O

    A. Kupers and O. Randal-Williams, On diffeomorphisms of even-dimensional discs, J. Amer. Math. Soc. 38 (2025), no. 1, 63--178. 4810061

  37. [45]

    R. C. Kirby and L. C. Siebenmann, Foundational essays on topological manifolds, smoothings, and triangulations, Annals of Mathematics Studies, No. 88, Princeton University Press, Princeton, N.J.; University of Tokyo Press, Tokyo, 1977, With notes by John Milnor and Michael Ati...

  38. [46]

    Khoroshkin and T

    A. Khoroshkin and T. Willwacher, Real models for the framed little n -disks operads, 2017, arXiv:1705.08108

  39. [47]

    Lurie, Higher topos theory, Annals of Mathematics Studies, vol

    J. Lurie, Higher topos theory, Annals of Mathematics Studies, vol. 170, Princeton University Press, 2009. 2522659

  40. [48]

    , Higher algebra , September 2017 version (2017)

  41. [49]

    , Spectral Algebraic Geometry , February 2018 version (2018)

  42. [50]

    Petersen, Minimal models, GT -action and formality of the little disk operad , Selecta Math

    D. Petersen, Minimal models, GT -action and formality of the little disk operad , Selecta Math. (N.S.) 20 (2014), no. 3, 817--822. 3217461

  43. [51]

    Pstragowski, Moduli of spaces with prescribed homotopy groups, J

    P. Pstragowski, Moduli of spaces with prescribed homotopy groups, J. Pure Appl. Algebra 227 (2023), no. 10, Paper No. 107409, 57. 4576887

  44. [52]

    Randal-Williams, An upper bound for the pseudoisotopy stable range, Math

    O. Randal-Williams, An upper bound for the pseudoisotopy stable range, Math. Ann. 368 (2017), no. 3-4, 1081--1094. 3673647

  45. [53]

    (N.S.) 24 (2018), no

    , Some phenomena in tautological rings of manifolds, Selecta Math. (N.S.) 24 (2018), no. 4, 3835--3873. 3848035

  46. [54]

    , A note on the family signature theorem, 2019, https://www.dpmms.cam.ac.uk/ or257/FamilySignature.pdf

  47. [55]

    , The family signature theorem, Proc. Roy. Soc. Edinburgh Sect. A 154 (2024), no. 6, 2024--2067. 4883996

  48. [56]

    J. A. Schafer, Topological P ontrjagin classes , Comment. Math. Helv. 45 (1970), 315--332. 275443

  49. [57]

    L. C. Siebenmann, Topological manifolds, Actes du C ongr\`es I nternational des M ath\' e maticiens ( N ice, 1970), T ome 2, Gauthier-Villars \' E diteur, Paris, 1971, pp. 133--163. 423356

  50. [58]

    D. P. Sinha, The (non-equivariant) homology of the little disks operad, O PERADS 2009, S\' e min. Congr., vol. 26, Soc. Math. France, Paris, 2013, pp. 253--279. 3203375

  51. [59]

    Stewart, Equivariant operads, symmetric sequences, and B oardman- V ogt tensor products , 2025, arXiv:2501.02129

    N. Stewart, Equivariant operads, symmetric sequences, and B oardman- V ogt tensor products , 2025, arXiv:2501.02129

  52. [60]

    D. P. Sullivan, Geometric topology: localization, periodicity and G alois symmetry , K -Monographs in Mathematics, vol. 8, Springer, Dordrecht, 2005, The 1970 MIT notes. 2162361

  53. [61]

    T. M. Schlank and L. Yanovski, The -categorical E ckmann- H ilton argument , Algebr. Geom. Topol. 19 (2019), no. 6, 3119--3170. 4023337

  54. [62]

    Tillmann and M

    S. Tillmann and M. S. Weiss, Occupants in manifolds, Manifolds and K -theory, Contemp. Math., vol. 682, Amer. Math. Soc., Providence, RI, 2017, pp. 237--259. 3603901

  55. [63]

    Watanabe, On K ontsevich's characteristic classes for higher-dimensional sphere bundles

    T. Watanabe, On K ontsevich's characteristic classes for higher-dimensional sphere bundles. II . H igher classes , J. Topol. 2 (2009), no. 3, 624--660. 2546588

  56. [64]

    , Addendum to: Some exotic nontrivial elements of the rational homotopy groups of Diff(S^4) (homological interpretation) , arXiv:2109.01609

  57. [65]

    , On K ontsevich's characteristic classes for higher-dimensional sphere bundles II : higher classes ( J . T opol. 2 (2009), no. 3, 624--660) [ C orrigendum] , J. Topol. 15 (2022), no. 1, 347--357. 4503959

  58. [66]

    Weiss, Embeddings from the point of view of immersion theory

    M. Weiss, Embeddings from the point of view of immersion theory. I , Geom. Topol. 3 (1999), 67--101. 1694812

  59. [67]

    , Configuration categories and homotopy automorphisms, Glasg. Math. J. 62 (2020), no. 1, 13--41. 4038997

  60. [68]

    , Rational P ontryagin classes of E uclidean fiber bundles , Geom. Topol. 25 (2021), no. 7, 3351--3424. 4372633

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