Reduced symplectic homology and string topology
Pith reviewed 2026-05-24 10:41 UTC · model grok-4.3
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.
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
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.
Referee Report
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)
- [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.
- [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)
- 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.
- 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
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
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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
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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
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
free parameters (1)
- choices governed by secondary continuation maps
axioms (1)
- domain assumption Existence of a suitable class of Weinstein manifolds admitting reduced symplectic homology
invented entities (1)
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reduced loop homology
no independent evidence
Lean theorems connected to this paper
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IndisputableMonolith/Cost/FunctionalEquation.leanwashburn_uniqueness_aczel unclear?
unclearRelation 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.
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IndisputableMonolith/Foundation/RealityFromDistinction.leanreality_from_one_distinction unclear?
unclearRelation 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.
What do these tags mean?
- matches
- The paper's claim is directly supported by a theorem in the formal canon.
- supports
- The theorem supports part of the paper's argument, but the paper may add assumptions or extra steps.
- extends
- The paper goes beyond the formal theorem; the theorem is a base layer rather than the whole result.
- uses
- The paper appears to rely on the theorem as machinery.
- contradicts
- 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
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[1]
M. Chas and D. Sullivan. String topology. arXiv:math/9911159, 19 99
work page internal anchor Pith review Pith/arXiv arXiv
-
[2]
K. Cieliebak and Y. Eliashberg. From Stein to Weinstein and back , volume 59 of American Mathematical Society Colloquium Publications . American Mathe- matical Society, Providence, RI, 2012. Symplectic geometry of affi ne complex manifolds
work page 2012
-
[3]
K. Cieliebak, N. Hingston, and A. Oancea. Loop coproduct in Mors e and Floer homology. arXiv:2008.13168
-
[4]
Poincar\'e duality for loop spaces
K. Cieliebak, N. Hingston, and A. Oancea. Poincar´ e duality for loo p spaces. arXiv:2008.13161
work page internal anchor Pith review Pith/arXiv arXiv 2008
-
[5]
K. Cieliebak and A. Oancea. CoFrobenius bialgebras, Poincar´ e du ality, and graded TQFT. Preprint 2022
work page 2022
-
[6]
K. Cieliebak and A. Oancea. Multiplicative structures on cones and duality. arXiv:2008.13165
-
[7]
K. Cieliebak and A. Oancea. Symplectic homology and the Eilenberg– Steenrod axioms. Algebr. Geom. Topol., 18(4):1953–2130, 2018
work page 1953
-
[8]
T. Ekholm and Y. Lekili. Duality between Lagrangian and Legendrian invari- ants. arXiv:1701.01284, 2017
-
[9]
T. Ekholm and A. Oancea. Symplectic and contact differential gra ded algebras. Geom. Topol., 21(4):2161–2230, 2017
work page 2017
-
[10]
A. Fauck. Rabinowitz-Floer homology on Brieskorn manifolds . PhD thesis, Humboldt-Universit¨ at zu Berlin, April 2016. arXiv:1605.07892
work page internal anchor Pith review Pith/arXiv arXiv 2016
-
[11]
M. Goresky and N. Hingston. Loop products and closed geodes ics. Duke Math. J., 150(1):117–209, 2009
work page 2009
-
[12]
J.-L. Loday and M. Ronco. On the structure of cofree Hopf alg ebras. J. Reine Angew. Math. , 592:123–155, 2006
work page 2006
-
[13]
D. Sullivan. Open and closed string field theory interpreted in clas sical alge- braic topology. In Topology, geometry and quantum field theory , volume 308 of London Math. Soc. Lecture Note Ser. , pages 344–357. Cambridge Univ. Press, Cambridge, 2004. REDUCED SYMPLECTIC HOMOLOGY 55
work page 2004
-
[14]
The Stacks project authors. The Stacks project. Section 1 .4.14 “Limits and colimits”. https://stacks.math.columbia.edu/tag/002D, 2022
work page 2022
-
[15]
P. Uebele. Symplectic homology of some Brieskorn manifolds. Math. Z., 283(1- 2):243–274, 2016
work page 2016
-
[16]
I. Ustilovsky. Infinitely many contact structures on S4m`1. Internat. Math. Res. Notices, (14):781–791, 1999
work page 1999
- [17]
-
[18]
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
work page 2018
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