pith. sign in

arxiv: 2510.15074 · v4 · submitted 2025-10-16 · 🧮 math.CO

(Treewidth, Clique)-Boundedness and Poly-logarithmic Tree-Independence

Pith reviewed 2026-05-18 05:59 UTC · model grok-4.3

classification 🧮 math.CO
keywords tree-independence numbertreewidthindependence containersgraph algorithmsDallard-Milanič-Štorgel conjecturebounded clique numberpoly-logarithmic bounds
0
0 comments X

The pith

A slight variant of the Dallard-Milanič-Štorgel conjecture holds and preserves its algorithmic consequences for graphs.

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

The paper establishes that a modified form of a conjecture relating tree-independence number to treewidth remains valid. This variant keeps the key algorithmic advantages that motivated the original conjecture even though the full conjecture was recently disproved. The authors introduce independence-containers as a generalization of maximal cliques to help prove the result. A sympathetic reader would care because bounded tree-independence number yields efficient algorithms for hard problems such as independent set on restricted graph classes.

Core claim

We prove a slight variant of the Dallard-Milanič-Štorgel conjecture connecting tree-independence number to the classical notion of treewidth. This variant retains much of the algorithmic significance of the original statement. As part of the proof we introduce the notion of independence-containers, which can be viewed as a generalization of the set of all maximal cliques of a graph and is of independent interest.

What carries the argument

Independence-containers, a generalization of the set of all maximal cliques that supports bounding independent sets in tree-decomposition bags.

If this is right

  • Algorithmic results that previously relied on the original conjecture continue to hold under the variant.
  • Graphs with bounded treewidth and bounded clique number admit tree decompositions whose bags have independent-set size bounded by a poly-logarithmic function.
  • The new independence-container concept supplies a tool for deriving further bounds on tree-independence number.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • The result may extend to other width parameters that combine treewidth with clique constraints.
  • Independence-containers could be applied directly to obtain approximation algorithms for independent-set problems without full tree decompositions.
  • The approach suggests testing whether similar mild variants rescue other recently disproved width conjectures.

Load-bearing premise

The particular modification made to the original Dallard-Milanič-Štorgel conjecture is close enough to preserve the stated algorithmic consequences.

What would settle it

A graph class with bounded treewidth and clique number whose minimum tree-independence number grows faster than any poly-logarithmic function of the input size.

read the original abstract

An independent set in a graph $G$ is a set of pairwise non-adjacent vertices. A tree decomposition of $G$ is a pair $(T, \chi)$ where $T$ is a tree and $\chi : V(T) \rightarrow 2^{V(G)}$ is a function satisfying the following two axioms: for every edge $uv \in V(G)$ there is a $x \in V(T)$ such that $\{u,v\} \subseteq \chi(x)$, and for every vertex $u \in V(G)$ the set $\{x \in V(T) ~:~ u \in \chi(X)\}$ induces a non-empty and connected subtree of $T$. The sets $\chi(x)$ for $x \in V(T)$ are called the bags of the tree decomposition. The tree-independence number of $G$ is the minimum taken over all tree decompositions of $G$ of the maximum size of an independent set of the graph induced by a bag of the tree decomposition. The study of graph classes with bounded tree-independence number has attracted much attention in recent years, in part due its improtant algorithmic implications. A conjecture of Dallard, Milani\v{c} and \v{S}torgel, connecting tree-independence number to the classical notion of treewidth, was one of the motivating problems in the area. This conjecture was recently disproved, but here we prove a slight variant of it, that retains much of the algorithmic significance. As part of the proof we introduce the notion of independence-containers, which can be viewed as a generalization of the set of all maximal cliques of a graph, and is of independent interest.

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 / 0 minor

Summary. The paper proves a slight variant of the disproved Dallard-Milanič-Štorgel conjecture, showing that (treewidth, clique)-bounded graph classes admit poly-logarithmic tree-independence number. It introduces independence-containers as a generalization of maximal cliques and uses them to establish the variant while claiming retention of much of the original conjecture's algorithmic significance.

Significance. If the variant is correctly formulated and the proof holds, the result would provide a usable substitute for the original conjecture, enabling algorithmic applications such as FPT algorithms or poly-logarithmic approximations for independent set and related problems in (tw, ω)-bounded classes via tree decompositions with small independent sets in bags.

major comments (2)
  1. The manuscript must explicitly state the precise formulation of the slight variant of the Dallard-Milanič-Štorgel conjecture (currently only alluded to in the abstract) and include a reduction or meta-theorem showing that the new bound on tree-independence number implies the same algorithmic corollaries (e.g., FPT or approximation results) that would have followed from the original conjecture. This comparison is load-bearing for the central claim that the variant 'retains much of the algorithmic significance.'
  2. The construction and properties of independence-containers (introduced as a generalization of maximal cliques) require a detailed verification that they suffice for the tree-decomposition arguments in the variant; without an explicit check that the algorithmic reductions from bounded tree-independence survive the change, the claim remains unanchored.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for their careful reading of the manuscript and for the constructive major comments. We agree that additional explicit statements and verifications will strengthen the presentation and will incorporate them in the revised version.

read point-by-point responses
  1. Referee: The manuscript must explicitly state the precise formulation of the slight variant of the Dallard-Milanič-Štorgel conjecture (currently only alluded to in the abstract) and include a reduction or meta-theorem showing that the new bound on tree-independence number implies the same algorithmic corollaries (e.g., FPT or approximation results) that would have followed from the original conjecture. This comparison is load-bearing for the central claim that the variant 'retains much of the algorithmic significance.'

    Authors: We agree that the precise formulation of the variant should be stated explicitly in the introduction. The variant of the Dallard-Milanič-Štorgel conjecture proved in the paper asserts that every (treewidth, clique)-bounded graph class has poly-logarithmic tree-independence number. In the revision we will add a meta-theorem (new Section 5) showing that a poly-logarithmic bound on tree-independence number yields the same FPT algorithms and poly-logarithmic approximations for independent set and related problems that would have followed from a bounded tree-independence number, with only a mild worsening of the running time from polynomial to n^{O(log n)}. revision: yes

  2. Referee: The construction and properties of independence-containers (introduced as a generalization of maximal cliques) require a detailed verification that they suffice for the tree-decomposition arguments in the variant; without an explicit check that the algorithmic reductions from bounded tree-independence survive the change, the claim remains unanchored.

    Authors: We thank the referee for this suggestion. Independence-containers are introduced in Section 3 as a generalization of the family of maximal cliques and are used to build the tree decompositions whose bags have poly-logarithmic independence number. In the revised manuscript we will expand Section 3 with a new subsection that verifies in detail the required properties of independence-containers and explicitly confirms that the standard algorithmic reductions from bounded tree-independence number carry over to the poly-logarithmic case, thereby anchoring the algorithmic claims. revision: yes

Circularity Check

0 steps flagged

No significant circularity detected

full rationale

The manuscript introduces independence-containers as a new combinatorial object generalizing maximal cliques and uses them to establish a slight variant of the Dallard-Milanič-Štorgel conjecture. The derivation proceeds via direct proof from standard tree-decomposition axioms and the newly defined containers rather than any self-referential definition, fitted parameter renamed as prediction, or load-bearing self-citation chain. The abstract explicitly frames the result as an independent proof that retains algorithmic consequences without reducing the claimed bound to its own inputs by construction.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 1 invented entities

Relies on standard definitions of tree decompositions, independent sets, and treewidth from prior graph theory literature; introduces independence-containers as a new tool for the proof.

axioms (1)
  • standard math Standard axioms for tree decompositions: every edge covered by some bag and vertex appearances form connected subtrees.
    Invoked in the definition of tree-independence number.
invented entities (1)
  • independence-containers no independent evidence
    purpose: Generalization of the set of all maximal cliques used to prove the poly-log bound.
    New object introduced in the paper; no independent evidence outside the proof is mentioned.

pith-pipeline@v0.9.0 · 5854 in / 1187 out tokens · 28539 ms · 2026-05-18T05:59:48.056345+00:00 · methodology

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Lean theorems connected to this paper

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

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.

Forward citations

Cited by 1 Pith paper

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score.

  1. Tree-alpha and excluding finitely many graphs

    math.CO 2026-05 unverdicted novelty 8.0

    Hereditary classes defined by finitely many excluded induced subgraphs have bounded tree-α iff they are (tw,ω)-bounded, i.e., exclude K_{a,a}, forests with components of at most three leaves, and their line graphs.

Reference graph

Works this paper leans on

25 extracted references · 25 canonical work pages · cited by 1 Pith paper

  1. [1]

    Pascal Gollin, Tony Huynh, and O-joung Kwon

    Jungho Ahn, J. Pascal Gollin, Tony Huynh, and O-joung Kwon. A coarse Erd˝ os-P´ osa theorem. In Yossi Azar and Debmalya Panigrahi, editors,Proceedings of the 2025 Annual ACM-SIAM Symposium on Discrete Algorithms, SODA 2025, New Orleans, LA, USA, January 12-15, 2025, pages 3363–3381. SIAM, 2025

  2. [2]

    On graphs with polynomially solvable maximum-weight clique problem.Net- works, 19(2):247–253, 1989

    Egon Balas and Chang Sung Yu. On graphs with polynomially solvable maximum-weight clique problem.Net- works, 19(2):247–253, 1989

  3. [3]

    The method of hypergraph containers

    J´ ozsef Balogh, Robert Morris, and Wojciech Samotij. The method of hypergraph containers. InProceedings of the International Congress of Mathematicians: Rio de Janeiro 2018, pages 3059–3092. World Scientific, 2018

  4. [4]

    A partial k-arboretum of graphs with bounded treewidth.Theoretical computer science, 209(1-2):1–45, 1998

    Hans L Bodlaender. A partial k-arboretum of graphs with bounded treewidth.Theoretical computer science, 209(1-2):1–45, 1998

  5. [5]

    Sparse graphs with bounded induced cycle packing number have logarithmic treewidth.J

    Marthe Bonamy, ´Edouard Bonnet, Hugues D´ epr´ es, Louis Esperet, Colin Geniet, Claire Hilaire, St´ ephan Thomass´ e, and Alexandra Wesolek. Sparse graphs with bounded induced cycle packing number have logarithmic treewidth.J. Combin. Theory Ser. B, 167:215–249, 2024

  6. [6]

    Tree independence number IV

    Maria Chudnovsky, Peter Gartland, Sepehr Hajebi, Daniel Lokshtanov, and Sophie Spirkl. Tree independence number IV. even-hole-free graphs. In Yossi Azar and Debmalya Panigrahi, editors,Proceedings of the 2025 Annual ACM-SIAM Symposium on Discrete Algorithms, SODA 2025, New Orleans, LA, USA, January 12-15, 2025, pages 4444–4461. SIAM, 2025

  7. [7]

    Tree independence number II

    Maria Chudnovsky, Sepehr Hajebi, Daniel Lokshtanov, and Sophie Spirkl. Tree independence number II. Three- path-configurations.arxiv:2405.00265, 2024. 26 MARIA CHUDNOVSKY †, AJAYKRISHNAN E S ‡, AND DANIEL LOKSHTANOV‡

  8. [8]

    On treewidth and maximum cliques.arxiv:2405.07471, 2024

    Maria Chudnovsky and Nicolas Trotignon. On treewidth and maximum cliques.arxiv:2405.07471, 2024

  9. [9]

    Springer, 2015

    Marek Cygan, Fedor V Fomin, Lukasz Kowalik, Daniel Lokshtanov, D´ aniel Marx, Marcin Pilipczuk, Micha l Pilipczuk, and Saket Saurabh.Parameterized algorithms, volume 5. Springer, 2015

  10. [10]

    Treewidth versus clique number

    Cl´ ement Dallard, Martin Milanic, and Kenny Storgel. Treewidth versus clique number. II. tree-independence number.Journal of Combinatorial Theory, Series B, 164:404–442, 2024

  11. [11]

    Treewidth versus clique number

    Cl´ ement Dallard, Martin Milanic, and Kenny Storgel. Treewidth versus clique number. III. tree-independence number of graphs with a forbidden structure.Journal of Combinatorial Theory, Series B, 167:338–391, 2024

  12. [12]

    Ramsey-type theorems.Discrete Applied Mathematics, 25(1-2):37–52, 1989

    Paul Erd¨ os and Andr´ as Hajnal. Ramsey-type theorems.Discrete Applied Mathematics, 25(1-2):37–52, 1989

  13. [13]

    Graph minors and metric spaces

    Agelos Georgakopoulos and Panos Papasoglu. Graph minors and metric spaces. Preprint available athttps: //arxiv.org/abs/2305.07456, 2023

  14. [14]

    A guided tour of chernoff bounds.Information processing letters, 33(6):305– 308, 1990

    Torben Hagerup and Christine R¨ ub. A guided tour of chernoff bounds.Information processing letters, 33(6):305– 308, 1990

  15. [15]

    Width parameters beyond tree-width and their applications.The Computer Journal, 51(3):326–362, 2007

    Petr Hlinen´ y, Sang-il Oum, Detlef Seese, and Georg Gottlob. Width parameters beyond tree-width and their applications.The Computer Journal, 51(3):326–362, 2007

  16. [16]

    Efficient approx- imation of fractional hypertree width

    Viktoriia Korchemna, Daniel Lokshtanov, Saket Saurabh, Vaishali Surianarayanan, and Jie Xue. Efficient approx- imation of fractional hypertree width. In65th IEEE Annual Symposium on Foundations of Computer Science, FOCS 2024, Chicago, IL, USA, October 27-30, 2024, pages 754–779. IEEE, 2024

  17. [17]

    PhD thesis, The University of Bergen, 2024

    Tuukka Korhonen.Computing Width Parameters of Graphs. PhD thesis, The University of Bergen, 2024

  18. [18]

    Lima, Martin Milanic, Peter Mursic, Karolina Okrasa, Pawel Rzazewski, and Kenny Storgel

    Paloma T. Lima, Martin Milanic, Peter Mursic, Karolina Okrasa, Pawel Rzazewski, and Kenny Storgel. Tree decompositions meet induced matchings: Beyond max weight independent set. In Timothy M. Chan, Johannes Fischer, John Iacono, and Grzegorz Herman, editors,32nd Annual European Symposium on Algorithms, ESA 2024, September 2-4, 2024, Royal Holloway, London...

  19. [19]

    Cambridge university press, 2017

    Michael Mitzenmacher and Eli Upfal.Probability and computing: Randomization and probabilistic techniques in algorithms and data analysis. Cambridge university press, 2017

  20. [20]

    Frank P. Ramsey. On a Problem of Formal Logic.Proc. London Math. Soc. (2), 30(4):264–286, 1929

  21. [21]

    Neil Robertson and P. D. Seymour. Graph minors. XVI. Excluding a non-planar graph.J. Combin. Theory Ser. B, 89(1):43–76, 2003

  22. [22]

    Neil Robertson and Paul D. Seymour. Graph minors. XIII. the disjoint paths problem.J. Comb. Theory B, 63(1):65–110, 1995

  23. [23]

    Hypergraph containers.Inventiones mathematicae, 201(3):925–992, 2015

    David Saxton and Andrew Thomason. Hypergraph containers.Inventiones mathematicae, 201(3):925–992, 2015

  24. [24]

    (Theta, triangle)-free and (even hole,K 4)-free graphs—part 1: Layered wheels.J

    Ni Luh Dewi Sintiari and Nicolas Trotignon. (Theta, triangle)-free and (even hole,K 4)-free graphs—part 1: Layered wheels.J. Graph Theory, 97(4):475–509, 2021

  25. [25]

    Minor-matching hypertree width

    Nikola Yolov. Minor-matching hypertree width. In Artur Czumaj, editor,Proceedings of the Twenty-Ninth Annual ACM-SIAM Symposium on Discrete Algorithms, SODA 2018, New Orleans, LA, USA, January 7-10, 2018, pages 219–233. SIAM, 2018