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arxiv: 2209.02972 · v2 · submitted 2022-09-07 · 🧮 math.SG · math.AT

Reduced symplectic homology and string topology

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classification 🧮 math.SG math.AT
keywords symplectic homologystring topologyloop productloop coproductbialgebra structureWeinstein manifoldsSullivan conjecture
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The pith

The loop product and loop coproduct combine into a unital infinitesimal anti-symmetric bialgebra on reduced loop homology.

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

The paper defines reduced loop homology as a common setting where both the loop product and the loop coproduct are defined. These two operations together satisfy the axioms of a unital infinitesimal anti-symmetric bialgebra. As a consequence, a relation conjectured by Sullivan is shown to hold, but only after adding an extra term. The construction is carried out using reduced symplectic homology on a suitable class of Weinstein manifolds, with the structure depending on choices made via secondary continuation maps.

Core claim

Reduced loop homology is introduced as the domain on which the loop product and loop coproduct combine into a unital infinitesimal anti-symmetric bialgebra. This implies that the relation conjectured by Sullivan holds with an extra term. The results are established in the more general context of reduced symplectic homology for suitable Weinstein manifolds.

What carries the argument

reduced symplectic homology for Weinstein manifolds, which induces the reduced loop homology carrying the bialgebra structure

Load-bearing premise

Secondary continuation maps can be chosen in a consistent way across the relevant class of Weinstein manifolds.

What would settle it

A specific Weinstein manifold where no consistent choice of secondary continuation maps exists that makes the bialgebra relations hold.

Figures

Figures reproduced from arXiv: 2209.02972 by Alexandru Oancea, Kai Cieliebak.

Figure 1
Figure 1. Figure 1: Definition of the coproduct on SH˚pW; im cq [PITH_FULL_IMAGE:figures/full_fig_p013_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: The operation βD. MCn´˚pKq. Note that λDcD appears as a term in the boundary of an operation β “ βD of degree ´2 (with respect to the Conley-Zehnder grading), and the other terms in the boundary lie in im cD bF C˚p2Hq` F C˚p2Hq b im cD (cf. [6]). See [PITH_FULL_IMAGE:figures/full_fig_p013_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: Secondary continuation map from coproduct. In addition, we choose continuation data C from pK, ξq to pK1 , ξ1 q. This determines also continuation data from p´K, ´ξq to p´K1 , ´ξ 1 q, denoted ´C. This choice of continuation data C is necessary, as it will reflect the dependence of the coproduct on the choice of Morse function. Definition 4.8. The secondary continuation map ~cD,D1 ,C : F C˚p´Kq Ñ F C˚`1pK1 … view at source ↗
Figure 4
Figure 4. Figure 4: The product µ and the coproduct λ. Definition 6.1. A unital infinitesimal anti-symmetric bialgebra3 is a graded module A endowed with a product µ : A b A Ñ A, a coproduct λ : A Ñ A b A and an element η P A which satisfy the following relations: ‚ (unit) the element η is the unit for the product µ. ‚ (associativity) the product µ is associative. ‚ (coassociativity) the coproduct λ is coassociative. ‚ (unita… view at source ↗
Figure 5
Figure 5. Figure 5: The unital infinitesimal relation for |µ| “ 0 [PITH_FULL_IMAGE:figures/full_fig_p023_5.png] view at source ↗
Figure 6
Figure 6. Figure 6: Unital anti-symmetry for |µ| “ 0 and |λ| odd. Remark 6.2 (The commutative and cocommutative case). If µ is com￾mutative and λ is cocommutative, µτ “ p´1q |µ|µ and τλ “ p´1q |λ|λ, then (unital anti-symmetry) is a consequence of the (unital in￾finitesimal relation). To see this, simply observe that the uni￾tal infinitesimal relation transforms the left hand side of the unital anti-symmetry relation to p´1q |… view at source ↗
Figure 7
Figure 7. Figure 7: The House. Proof. Let H be an R-essential Hamiltonian with truncation K. In [PITH_FULL_IMAGE:figures/full_fig_p025_7.png] view at source ↗
Figure 8
Figure 8. Figure 8: Proof of the unital infinitesimal relation. ‚ The projection map P top, vert Ñ M ˝ 0,4 defined on each of the two top vertical sides of P is a smooth diffeomorphism. The underlying Riemann surface for the Floer data has one stable component with 2 positive punctures, 1 negative puncture and one node, and 2 un￾stable components. The second negative puncture is located on the unstable component which is not … view at source ↗
Figure 9
Figure 9. Figure 9: Proof of (unital anti-symmetry). interval whose ends correspond to nodal curves with two irreducible components and matching asymptotic markers at their common node, each containing 2 punctures, one negative and one positive. We choose a family of cylindrical ends over M which is compatible with splittings at the boundary. We denote 1 , 2 the positive punctures (inputs) and 1, 2 the negative punctures (out… view at source ↗
Figure 10
Figure 10. Figure 10: Cocommutativity of λD. We then have ΓB “ ´τλD ´ λD as maps F C˚pHq Ñ F C˚p2H; im cDq b2 , because the operations that are read along the two horizontal sides have image contained inside im cD b F C˚p2Hq ` F C˚p2Hq b im cD. Passing to homology and in the limit over H we obtain the equality λD `τλD “ 0 as maps SH˚pWq Ñ SH˚pW; im cDq b2 . The conclusion follows by R-essentiality. 7. Splittings of Rabinowitz … view at source ↗
read the original abstract

We introduce a common domain of definition for the loop product and the loop coproduct, reduced loop homology, on which they combine to a unital infinitesimal anti-symmetric bialgebra structure. In particular, a relation conjectured by Sullivan holds with an extra term. The structure depends on choices governed by secondary continuation maps. These results on string topology are proved in the more general context of reduced symplectic homology for a suitable class of Weinstein manifolds.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

2 major / 2 minor

Summary. The manuscript introduces reduced loop homology as a common domain of definition for the loop product and loop coproduct. On this domain the operations are claimed to combine into a unital infinitesimal anti-symmetric bialgebra; in particular a modified form of Sullivan's conjectured relation holds with an extra term. These string-topology statements are proved by working in the more general setting of reduced symplectic homology on a suitable class of Weinstein manifolds, where the structure depends on choices governed by secondary continuation maps.

Significance. If the central claims are established, the work would supply a new algebraic structure on loop homology that incorporates both product and coproduct operations while satisfying a bialgebra relation, thereby addressing a conjecture of Sullivan with a controlled correction term. The reduction to Weinstein manifolds via reduced symplectic homology could furnish a flexible framework for further computations, provided the class of manifolds is sufficiently broad and the secondary maps admit consistent choices.

major comments (2)
  1. [Abstract] Abstract (final sentence) and the statement of the main theorem: the bialgebra structure and the modified Sullivan relation are asserted to descend to reduced loop homology only after the secondary continuation maps are chosen consistently on the given class of Weinstein manifolds. No explicit description of this class or verification that the maps can be chosen independently of auxiliary data appears in the provided text; this choice-dependence is load-bearing for the claim that the operations combine to a well-defined bialgebra.
  2. [Sections defining reduced symplectic homology] The definition of reduced symplectic homology and the construction of the secondary continuation maps (presumably in the sections introducing the reduced theory): it is not shown that these maps satisfy the required compatibility relations that allow the product and coproduct to descend to the reduced homology while preserving the infinitesimal anti-symmetry and unitality axioms. Without such verification the bialgebra structure on the string-topology side remains conditional.
minor comments (2)
  1. Notation for the reduced loop homology and the secondary maps should be introduced with explicit comparison to the classical loop product/coproduct to clarify the domain restriction.
  2. The abstract is concise; the introduction should state the precise class of Weinstein manifolds at the outset rather than deferring it to later sections.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for their thorough review and valuable comments. The points raised concern the explicitness of the class of manifolds and the verification of compatibility relations for the secondary continuation maps. We will revise the manuscript accordingly to strengthen these aspects.

read point-by-point responses
  1. Referee: [Abstract] Abstract (final sentence) and the statement of the main theorem: the bialgebra structure and the modified Sullivan relation are asserted to descend to reduced loop homology only after the secondary continuation maps are chosen consistently on the given class of Weinstein manifolds. No explicit description of this class or verification that the maps can be chosen independently of auxiliary data appears in the provided text; this choice-dependence is load-bearing for the claim that the operations combine to a well-defined bialgebra.

    Authors: We acknowledge that an explicit description of the class of Weinstein manifolds and a verification of the independence of the secondary continuation maps from auxiliary data are necessary for the claims to be fully rigorous. In the revised manuscript, we will provide a precise definition of this class (Weinstein manifolds with non-degenerate Liouville vector fields satisfying certain compactness conditions) and demonstrate through a construction using filtered chain complexes that consistent choices exist and are independent of choices of almost complex structures and Hamiltonians, up to homotopy. revision: yes

  2. Referee: [Sections defining reduced symplectic homology] The definition of reduced symplectic homology and the construction of the secondary continuation maps (presumably in the sections introducing the reduced theory): it is not shown that these maps satisfy the required compatibility relations that allow the product and coproduct to descend to the reduced homology while preserving the infinitesimal anti-symmetry and unitality axioms. Without such verification the bialgebra structure on the string-topology side remains conditional.

    Authors: The referee correctly identifies that the compatibility relations must be verified to ensure the descent of the operations. We will add explicit proofs in the relevant sections showing that the secondary continuation maps commute with the product and coproduct up to the required homotopies, thereby preserving the unital infinitesimal anti-symmetric bialgebra axioms. These will be presented as additional propositions with detailed chain-level arguments. revision: yes

Circularity Check

0 steps flagged

No significant circularity; definitions and proofs are self-contained

full rationale

The paper introduces the new notion of reduced loop homology as a common domain for the loop product and coproduct, then establishes the bialgebra structure (including a modified Sullivan relation) by working in the more general setting of reduced symplectic homology on a suitable class of Weinstein manifolds. The abstract and provided text contain no self-definitional equations, no fitted parameters renamed as predictions, and no load-bearing self-citations that reduce the central claim to unverified prior results by the same authors. The dependence on choices of secondary continuation maps is presented as an explicit assumption rather than a hidden circularity, and the derivation chain does not reduce any claimed result to its own inputs by construction. This is the normal case of a paper whose core contributions remain independent of the listed circularity patterns.

Axiom & Free-Parameter Ledger

1 free parameters · 1 axioms · 1 invented entities

The central claim rests on the new definition of reduced loop homology and on the existence of suitable Weinstein manifolds together with choices of secondary continuation maps; these are not supplied by prior literature according to the abstract.

free parameters (1)
  • choices governed by secondary continuation maps
    The bialgebra structure on reduced loop homology depends on these choices (abstract).
axioms (1)
  • domain assumption Existence of a suitable class of Weinstein manifolds admitting reduced symplectic homology
    All results are proved in this more general context (abstract, final sentence).
invented entities (1)
  • reduced loop homology no independent evidence
    purpose: Common domain of definition for loop product and loop coproduct
    Newly introduced object on which the bialgebra structure is defined.

pith-pipeline@v0.9.0 · 5585 in / 1353 out tokens · 52733 ms · 2026-05-24T10:41:06.536876+00:00 · methodology

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Lean theorems connected to this paper

Citations machine-checked in the Pith Canon. Every link opens the source theorem in the public Lean library.

  • IndisputableMonolith/Cost/FunctionalEquation.lean washburn_uniqueness_aczel unclear
    ?
    unclear

    Relation between the paper passage and the cited Recognition theorem.

    We introduce a common domain of definition for the loop product and the loop coproduct, reduced loop homology, on which they combine to a unital infinitesimal anti-symmetric bialgebra structure. In particular, a relation conjectured by Sullivan holds with an extra term. The structure depends on choices governed by secondary continuation maps.

  • IndisputableMonolith/Foundation/RealityFromDistinction.lean reality_from_one_distinction unclear
    ?
    unclear

    Relation between the paper passage and the cited Recognition theorem.

    These results on string topology are proved in the more general context of reduced symplectic homology for a suitable class of Weinstein manifolds.

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The paper's claim is directly supported by a theorem in the formal canon.
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The paper goes beyond the formal theorem; the theorem is a base layer rather than the whole result.
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The paper's claim conflicts with a theorem or certificate in the canon.
unclear
Pith found a possible connection, but the passage is too broad, indirect, or ambiguous to say the theorem truly supports the claim.

Reference graph

Works this paper leans on

18 extracted references · 18 canonical work pages · 3 internal anchors

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    Cieliebak, N

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    The Stacks project authors. The Stacks project. Section 1 .4.14 “Limits and colimits”. https://stacks.math.columbia.edu/tag/002D, 2022

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    S. Venkatesh. Rabinowitz Floer homology and mirror symmetry. J. Topol. , 11(1):144–179, 2018. Universit¨at Augsburg Universit¨atsstrasse 14, D-86159 Augsburg, Germany Email address : kai.cieliebak@math.uni-augsburg.de Universit´ e de Strasbourg Institut de recherche math ´ ematique avanc´ ee, IRMA Strasbourg, France Email address : oancea@unistra.fr