On L-space surgeries on two-bridge links
Pith reviewed 2026-06-26 01:52 UTC · model grok-4.3
The pith
The sets of L-space surgeries on all two-bridge links are classified, yielding the first hyperbolic examples that cannot be expressed as finite unions of rectangles in Q squared.
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
Core claim
We classify the sets of L-space surgeries on all two-bridge links, providing the first examples of hyperbolic links for which such sets cannot be described as unions of finitely many rectangles in Q^2. The proof relies on a sufficient diagrammatic condition for links in S^3 to be persistently foliar, a simplified model for the Heegaard Floer homology of rational surgeries on two-component L-space links, and explicit computations of Turaev torsions to determine L-space surgeries in the case of generalised L-space links.
What carries the argument
A diagrammatic condition for persistently foliar links that implies every nontrivial surgery supports a coorientable taut foliation, together with a simplified Heegaard Floer model for two-component L-space links and Turaev torsion computations.
If this is right
- An optimal uniform bound holds on the volume of any hyperbolic L-space obtained by surgery on a two-bridge link.
- All L-space satellite knots whose pattern is a two-bridge link are classified.
- The diagrammatic condition and simplified model apply to L-space surgery questions on links beyond the two-bridge case.
- New obstructions to L-space surgeries arise from the foliation condition and the Heegaard Floer model.
Where Pith is reading between the lines
- The same diagrammatic test could be applied to other link families to produce further non-rectangular examples.
- The existence of non-rectangular surgery sets on hyperbolic links suggests that rectangle unions are not the general shape for such sets.
- The volume bound may serve as a benchmark when comparing L-spaces from other link classes or surgery operations.
Load-bearing premise
The diagrammatic condition for persistently foliar links, the simplified Heegaard Floer model, and the Turaev torsion computations together determine the L-space surgeries for every two-bridge link without gaps.
What would settle it
A two-bridge link on which an explicit Heegaard Floer calculation produces an L-space surgery outside the sets predicted by the diagrammatic condition and torsion computations.
Figures
read the original abstract
We classify the sets of $L$-space surgeries on all two-bridge links, providing the first examples of hyperbolic links for which such sets cannot be described as unions of finitely many rectangles in $\mathbb{Q}^2$. The proof relies on several different techniques, each of which is applicable in greater generality: we introduce a sufficient diagrammatic condition for links in $S^3$ to be persistently foliar, a property that implies that every non-trivial surgery on such links supports a coorientable taut foliation. We define a simplified model for the Heegaard Floer homology of rational surgeries on two-component $L$-space links, following the work of Manolescu-Ozsv\'ath, Liu, and Zemke, and use it to obtain obstructions to $L$-space surgeries. Finally, we use explicit computations of Turaev torsions to determine $L$-space surgeries in the case of generalised $L$-space links. Among the consequences of our results, we obtain an optimal uniform bound on the volume of any hyperbolic $L$-space that is surgery on a two-bridge link, together with a classification of all $L$-space satellite knots whose associated two-component pattern link is a two-bridge link.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The manuscript classifies the sets of L-space surgeries on all two-bridge links, providing the first examples of hyperbolic links for which such sets cannot be described as unions of finitely many rectangles in Q^2. The proof relies on three techniques: a sufficient diagrammatic condition for links in S^3 to be persistently foliar (implying every non-trivial surgery supports a coorientable taut foliation), a simplified model for the Heegaard Floer homology of rational surgeries on two-component L-space links (following Manolescu-Ozsváth, Liu, and Zemke), and explicit computations of Turaev torsions to determine L-space surgeries for generalised L-space links. Consequences include an optimal uniform bound on the volume of any hyperbolic L-space that is surgery on a two-bridge link, together with a classification of all L-space satellite knots whose associated two-component pattern link is a two-bridge link.
Significance. If the classification holds, the result is significant for low-dimensional topology: it completes the picture for two-bridge links (a large, well-studied class) and supplies the first hyperbolic-link counterexamples to the “finite rectangles” description previously observed for knots and some links. The three techniques are each stated to apply more generally, and the manuscript supplies explicit computations, volume bounds, and a satellite-knot classification; these concrete outputs strengthen the contribution.
minor comments (3)
- [Introduction] The introduction of the diagrammatic condition for persistently foliar links would benefit from an explicit statement of the condition (e.g., as a numbered definition or theorem) together with a short example of a two-bridge link satisfying it.
- [Heegaard Floer section] In the section describing the simplified HF model, the precise relationship between the model and the earlier work of Manolescu-Ozsváth, Liu, and Zemke should be stated as a numbered proposition or lemma so that the obstructions derived from it are clearly traceable.
- [Turaev torsion section] The Turaev-torsion computations for generalised L-space links are central to one case of the classification; a brief table or list indicating which two-bridge links fall into this case would improve readability.
Simulated Author's Rebuttal
We thank the referee for their positive summary, significance assessment, and recommendation of minor revision. The report correctly identifies the main contributions: the classification for two-bridge links, the first hyperbolic-link counterexamples to the finite-rectangles description, and the three general techniques (persistent foliations, simplified HF model, Turaev torsions) together with the volume bound and satellite-knot classification. No specific major comments appear in the report, so we have no points to address point-by-point. We will incorporate any minor editorial suggestions in the revised version.
Circularity Check
No significant circularity; derivation uses independent external techniques
full rationale
The paper's classification rests on three distinct methods: a new diagrammatic condition for persistently foliar links (implying taut foliations), a simplified Heegaard Floer model for two-component L-space links (explicitly following Manolescu-Ozsváth, Liu, and Zemke), and explicit Turaev torsion computations for generalised L-space links. None of these steps is shown to reduce by definition or self-citation to the target classification; the cited prior works are independent and the techniques are described as complementary and applicable more generally. No fitted parameters, self-definitional loops, or load-bearing self-citations appear in the argument structure.
Axiom & Free-Parameter Ledger
Reference graph
Works this paper leans on
-
[1]
Hyperbolic four-manifolds with vanishing
Agol, Ian and Lin, Francesco , journal=. Hyperbolic four-manifolds with vanishing. 2020 , publisher=
2020
-
[2]
Foliations, orders, representations,
Boyer, Steven and Clay, Adam , journal=. Foliations, orders, representations,. 2017 , publisher=
2017
-
[3]
Boyer, Steven and Gordon, Cameron McA and Watson, Liam , journal=. On. 2013 , publisher=
2013
-
[4]
Dodecahedral
Battista, Ludovico and Ferrari, Leonardo and Santoro, Diego , journal=. Dodecahedral
-
[5]
preprint , year=
New geometric splittings of classical knots and the classification and symmetries of arborescent knots , author=. preprint , year=
-
[6]
Approximating
Bowden, Jonathan , journal=. Approximating. 2016 , publisher=
2016
-
[7]
2003 , publisher=
Knots , author=. 2003 , publisher=
2003
-
[8]
Fibered and strongly quasi-positive
Cavallo, Alberto and Liu, Beibei , journal=. Fibered and strongly quasi-positive. 2021 , publisher=
2021
-
[9]
arXiv preprint arXiv:2412.05755 , year=
L-space satellite operators and knot Floer homology , author=. arXiv preprint arXiv:2412.05755 , year=
-
[10]
Characters in Low-Dimensional Topology , volume=
Taut foliations from double-diamond replacements , author=. Characters in Low-Dimensional Topology , volume=. 2020 , publisher=
2020
-
[11]
Dawra, Nakul , year =. On the
-
[12]
Geometry & Topology , volume=
Fixed-point-free pseudo-Anosov homeomorphisms, knot Floer homology and the cinquefoil , author=. Geometry & Topology , volume=. 2024 , publisher=
2024
-
[13]
Ghiggini, Paolo , journal=. Knot. 2008 , publisher=
2008
-
[14]
2014 , publisher=
Greene, Joshua Evan , journal=. 2014 , publisher=
2014
-
[15]
International Mathematics Research Notices , volume=
Triple linking numbers and Heegaard Floer homology , author=. International Mathematics Research Notices , volume=. 2023 , publisher=
2023
-
[16]
1990 , publisher=
Gabai, David and Kazez, William H , journal=. 1990 , publisher=
1990
-
[17]
Annals of Mathematics , volume=
Essential laminations in 3-manifolds , author=. Annals of Mathematics , volume=. 1989 , publisher=
1989
-
[18]
Surgery on links of linking number zero and the
Gorsky, Eugene and Liu, Beibei and Moore, Allison H , journal=. Surgery on links of linking number zero and the
-
[19]
Algebraic & Geometric Topology , volume=
Gorsky, Eugene and N. Algebraic & Geometric Topology , volume=. 2016 , publisher=
2016
-
[20]
On the set of
Gorsky, Eugene and N. On the set of. Advances in Mathematics , volume=. 2018 , publisher=
2018
-
[21]
Gorsky, Eugene and N\'emethi, Andr\'as , TITLE =. Int. Math. Res. Not. IMRN , FJOURNAL =. 2015 , NUMBER =. doi:10.1093/imrn/rnv075 , URL =
-
[22]
Compositio Mathematica , volume=
L-spaces, taut foliations, and graph manifolds , author=. Compositio Mathematica , volume=. 2020 , publisher=
2020
-
[23]
Hanselman, Jonathan and Rasmussen, Jacob and Watson, Liam , TITLE =. J. Amer. Math. Soc. , FJOURNAL =. 2024 , NUMBER =. doi:10.1090/jams/1029 , URL =
-
[24]
Algebraic & Geometric Topology , volume=
Fundamental shadow links realized as links in S^3 , author=. Algebraic & Geometric Topology , volume=. 2021 , publisher=
2021
-
[25]
Gabai, David , TITLE =. J. Differential Geom. , FJOURNAL =. 1983 , NUMBER =
1983
-
[26]
Gabai, David , journal=
-
[27]
A note on
Hoste, Jim , journal=. A note on. 2020 , publisher=
2020
-
[28]
A survey of
Juh. A survey of. New ideas in low dimensional topology , pages=. 2015 , publisher=
2015
-
[29]
(1,1) non-
Lyu, Qingfeng , journal=. (1,1) non-
-
[30]
2017 , publisher=
Kazez, William and Roberts, Rachel , journal=. 2017 , publisher=
2017
-
[31]
Geometry & Topology , volume=
Laminar branched surfaces in 3--manifolds , author=. Geometry & Topology , volume=. 2002 , publisher=
2002
-
[32]
Proceedings of symposia in pure mathematics , volume=
Boundary train tracks of laminar branched surfaces , author=. Proceedings of symposia in pure mathematics , volume=. 2003 , organization=
2003
-
[33]
Journal of the European Mathematical Society , year=
Lattice homology, formality, and plumbed L-space links , author=. Journal of the European Mathematical Society , year=
-
[34]
Zemke, Ian , TITLE =. Duke Math. J. , FJOURNAL =. 2025 , NUMBER =. doi:10.1215/00127094-2024-0044 , URL =
-
[35]
1996 , PAGES =
Kawauchi, Akio , TITLE =. 1996 , PAGES =
1996
-
[36]
Cosmetic surgery in
Lidman, Tye and Moore, Allison , journal=. Cosmetic surgery in
-
[37]
Transactions of the London Mathematical Society , volume=
L-space surgeries on 2-component L-space links , author=. Transactions of the London Mathematical Society , volume=. 2021 , publisher=
2021
-
[38]
Liu, Yajing , TITLE =. Quantum Topol. , FJOURNAL =. 2017 , NUMBER =. doi:10.4171/QT/96 , URL =
-
[39]
Liu, Yajing , TITLE =. Algebr. Geom. Topol. , FJOURNAL =. 2022 , NUMBER =. doi:10.2140/agt.2022.22.473 , URL =
-
[40]
Notions of positivity and the
Hedden, Matthew , journal=. Notions of positivity and the. 2010 , publisher=
2010
-
[41]
Inventiones mathematicae , volume=
Right-veering diffeomorphisms of compact surfaces with boundary , author=. Inventiones mathematicae , volume=. 2007 , publisher=
2007
-
[42]
arXiv preprint arXiv:1011.1317 , year=
Heegaard Floer homology and integer surgeries on links , author=. arXiv preprint arXiv:1011.1317 , year=
-
[43]
Advances in Mathematics , volume=
Alternating knots with unknotting number one , author=. Advances in Mathematics , volume=. 2017 , publisher=
2017
-
[44]
2007 , publisher=
Ni, Yi , journal=. 2007 , publisher=
2007
-
[45]
Ozsv\'ath, Peter and Szab\'o, Zolt\'an , TITLE =. Ann. of Math. (2) , FJOURNAL =. 2004 , NUMBER =. doi:10.4007/annals.2004.159.1027 , URL =
-
[46]
Ozsv\'ath, Peter and Szab\'o, Zolt\'an , TITLE =. Ann. of Math. (2) , FJOURNAL =. 2004 , NUMBER =. doi:10.4007/annals.2004.159.1159 , URL =
-
[47]
and Szab\'o, Zolt\'an , TITLE =
Ozsv\'ath, Peter S. and Szab\'o, Zolt\'an , TITLE =. Algebr. Geom. Topol. , FJOURNAL =. 2008 , NUMBER =. doi:10.2140/agt.2008.8.101 , URL =
-
[48]
Algebraic & Geometric Topology , volume=
A note on cabling and L--space surgeries , author=. Algebraic & Geometric Topology , volume=. 2011 , publisher=
2011
-
[49]
and Szab\'o, Zolt\'an , TITLE =
Ozsv\'ath, Peter S. and Szab\'o, Zolt\'an , TITLE =. Algebr. Geom. Topol. , FJOURNAL =. 2011 , NUMBER =. doi:10.2140/agt.2011.11.1 , URL =
-
[50]
and Szab\'o, Zolt\'an , TITLE =
Ozsv\'ath, Peter and Stipsicz, Andr\'as I. and Szab\'o, Zolt\'an , TITLE =. Quantum Topol. , FJOURNAL =. 2014 , NUMBER =. doi:10.4171/QT/56 , URL =
-
[51]
Ozsv. On knot. Topology , volume=. 2005 , publisher=
2005
-
[52]
Geometry & Topology , volume=
Holomorphic disks and genus bounds , author=. Geometry & Topology , volume=. 2004 , publisher=
2004
-
[53]
Topology , volume=
Closed incompressible surfaces in alternating knot and link complements , author=. Topology , volume=. 1984 , publisher=
1984
-
[54]
Lisca, Paolo and Mati\'c, Gordana , TITLE =. Algebr. Geom. Topol. , FJOURNAL =. 2004 , PAGES =. doi:10.2140/agt.2004.4.1125 , URL =
-
[55]
Hedden, Matthew and Levine, Adam Simon , TITLE =. Quantum Topol. , FJOURNAL =. 2024 , NUMBER =. doi:10.4171/qt/188 , URL =
-
[56]
Ozsv\'ath, Peter and Szab\'o, Zolt\'an , TITLE =. Adv. Math. , FJOURNAL =. 2004 , NUMBER =. doi:10.1016/j.aim.2003.05.001 , URL =
-
[57]
Ozsv\'ath, Peter and Szab\'o, Zolt\'an , TITLE =. Algebr. Geom. Topol. , FJOURNAL =. 2008 , NUMBER =. doi:10.2140/agt.2008.8.615 , URL =
-
[58]
Transactions of the American Mathematical Society , volume=
A calculus for plumbing applied to the topology of complex surface singularities and degenerating complex curves , author=. Transactions of the American Mathematical Society , volume=
-
[59]
Compositio Mathematica , volume=
L-space intervals for graph manifolds and cables , author=. Compositio Mathematica , volume=. 2017 , publisher=
2017
-
[60]
Proceedings of the London Mathematical Society , volume=
Taut foliations in punctured surface bundles, II , author=. Proceedings of the London Mathematical Society , volume=. 2001 , publisher=
2001
-
[61]
Proceedings of the London Mathematical Society , volume=
Taut foliations in punctured surface bundles, I , author=. Proceedings of the London Mathematical Society , volume=. 2000 , publisher=
2000
-
[62]
Floer simple manifolds and
Rasmussen, Jacob and Rasmussen, Sarah Dean , journal=. Floer simple manifolds and. 2017 , publisher=
2017
-
[63]
Knoten mit zwei Br
Schubert, Horst , journal=. Knoten mit zwei Br. 1956 , publisher=
1956
-
[64]
Turaev, Vladimir , TITLE =. 2002 , PAGES =. doi:10.1007/978-3-0348-7999-6 , URL =
-
[65]
Zemke, Ian , TITLE =. J. Topol. , FJOURNAL =. 2019 , NUMBER =. doi:10.1112/topo.12085 , URL =
-
[66]
A general
Zemke, Ian , journal=. A general
-
[67]
arXiv preprint arXiv:2109.11520 , year=
Bordered manifolds with torus boundary and the link surgery formula , author=. arXiv preprint arXiv:2109.11520 , year=
-
[68]
Proceedings of the London Mathematical Society , volume=
The volume of hyperbolic alternating link complements , author=. Proceedings of the London Mathematical Society , volume=. 2004 , publisher=
2004
-
[69]
Lipshitz, Robert and Ozsvath, Peter S. and Thurston, Dylan P. , TITLE =. Mem. Amer. Math. Soc. , FJOURNAL =. 2018 , NUMBER =. doi:10.1090/memo/1216 , URL =
-
[70]
Lipshitz, Robert and Ozsv\'ath, Peter S. and Thurston, Dylan P. , TITLE =. Geom. Topol. , FJOURNAL =. 2015 , NUMBER =. doi:10.2140/gt.2015.19.525 , URL =
-
[71]
, TITLE =
Lipshitz, Robert and Ozsv\'ath, Peter and Thurston, Dylan P. , TITLE =. Studia Sci. Math. Hungar. , FJOURNAL =. 2025 , NUMBER =
2025
-
[72]
Lisca, Paolo and Stipsicz, Andr\'as I. , TITLE =. J. Symplectic Geom. , FJOURNAL =. 2007 , NUMBER =. doi:10.4310/jsg.2007.v5.n4.a1 , URL =
-
[73]
Rational
Rasmussen, Sarah Dean , journal=. Rational. 2020 , publisher=
2020
-
[74]
Santoro, Diego , TITLE =. Algebr. Geom. Topol. , FJOURNAL =. 2024 , NUMBER =. doi:10.2140/agt.2024.24.3455 , URL =
-
[75]
Santoro, Diego , TITLE =. Algebr. Geom. Topol. , FJOURNAL =. 2026 , NUMBER =. doi:10.2140/agt.2026.26.1115 , URL =
-
[76]
Advances in Mathematics , volume =
Taut foliations from knot diagrams , author =. Advances in Mathematics , volume =. 2026 , issn =. doi:https://doi.org/10.1016/j.aim.2026.110906 , url =
-
[77]
, TITLE =
Stallings, John R. , TITLE =. Algebraic and geometric topology (. 1978 , ISBN =
1978
-
[78]
2022 , publisher=
Thurston, William P , volume=. 2022 , publisher=
2022
-
[79]
Saito, Toshio , TITLE =. Osaka J. Math. , FJOURNAL =. 2004 , NUMBER =
2004
-
[80]
Mathematische Annalen , volume=
On unknotting tunnels for knots , author=. Mathematische Annalen , volume=. 1991 , publisher=
1991
discussion (0)
Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.