REVIEW 3 major objections 6 minor 2 cited by
Weakly branch actions: first-order theory, rigidity and Boston's conjecture
T0 review · 3 major / 6 minor · reviewed 2026-08-06 · deepseek-v4-flash
Pith's one-line read The paper seeks to disprove Boston's conjecture by showing that just-infinite branch pro-$p$ groups $G_n$ admit only zero-dimensional branch actions on the $p$-adic tree.
desk verdict A substantial paper that likely kills Boston's 25-year-old conjecture, but the disproof leans on unstated results from the author's earlier paper and on one uncited structural fact; the referee should check those before signing off. read the letter →
The pith
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
The reading
What carries the argument
The central object is the structure graph of a weakly branch group, a graph whose vertices are equivalence classes of basal subgroups, where two basal subgroups are equivalent if they have non-trivial intersection and equal normalizers. A basal subgroup is one with finitely many conjugates whose normal closure is the direct product of its distinct conjugates; rigid vertex stabilizers are the standard examples. The structure graph encodes all weakly branch actions of a group on spherically homogeneous rooted trees. Rigidity is characterized through $T$-filtrations: a weakly branch group is $T$-rigid exactly when the family $\mathcal{F}_T$ of subgroups appearing in $T$-filtrations coincides with the set of vertex stabilizers of the action. The disproof of Boston's conjecture applies this characterization to prove $T_n$-rigidity of $G_n$; the proof is carried by a dichotomy that forces any finite-index subgroup of $G_n$ containing a deep vertex stabilizer to contain a level stabilizer.
What would settle it
Exhibit a branch action $\chi: G_n \to W_p$ with positive Hausdorff dimension, or equivalently a finite-index subgroup $H \leq G_n$ with $|G_n:H| \leq p^{\ell_n}$ that contains a vertex stabilizer at level $t_n^2$ of $T_p$ but not the level stabilizer $\mathrm{St}_{\rho_n}(t_n^1)$. Lemma 6.3 rules out such $H$, and this dichotomy is the step that transfers rigidity into the index equalities that force dimension zero.
Extended reading notes
Core claim
On the paper's own terms, the discovery is that positive Hausdorff dimension is not an intrinsic feature of just-infinite branch pro-$p$ groups. For every $n \geq 1$, the closure in $W_p$ of the just-infinite branch group $G_n$ is a counterexample to Boston's conjecture: it is branch and just-infinite, and every branch action of $G_n$ on the $p$-adic tree has Hausdorff dimension zero. The proof establishes $T_n$-rigidity of $G_n$, meaning the induced action on the deleted-level tree $T_n$ is unique up to conjugation, and then compares level-stabilizer indices along the deleted levels $t_n^k$: rigidity makes the index sequence of any branch action on $T_p$ coincide with that of the original action, whose Hausdorff dimension was already known to be zero. Hence no embedding of $G_n$ into $W_p$ with positive Hausdorff dimension exists.
Load-bearing premise
The disproof rests on the author's earlier results that the groups $G_n$ are just-infinite branch pro-$p$ groups and that their closures in $W_p$ have Hausdorff dimension zero, together with the formula computing Hausdorff dimension from level-stabilizer indices; if any of those imported results fails, the counterexample to Boston's conjecture collapses.
Editorial extensions
If this is right
- Boston's conjecture is false: there exist just-infinite branch pro-$p$ groups with no positive-dimensional embedding into $W_p$.
- Every branch action of $G_n$ on the $p$-adic tree is zero-dimensional, so zero Hausdorff dimension is a feature of the abstract group, not merely of one chosen embedding.
- The congruence topology and the structure graph are first-order definable in any weakly branch group, and level stabilizers are first-order definable whenever the action is rigid.
- A fractal weakly branch group $G \leq W_p$ is $T_p$-rigid exactly when $G/\mathrm{St}_G(2) \ncong C_p \times C_p$; in particular, Hausdorff dimension larger than $1/p$ forces rigidity, and the threshold is sharp.
- A weakly branch group is $T$-rigid exactly when its congruence completion is $T$-rigid, so rigidity passes between a group and its profinite completion for these actions.
Reading between the lines
- Going beyond the paper: if the answer to its Question 8 is yes, then every weakly branch group would have some rigid action on a deleted-level tree, turning the proof into a general recipe for reducing questions about arbitrary branch actions to a single rigid action.
- Going beyond the paper: the rigidity-versus-dimension threshold at $1/p$ suggests that Hausdorff dimension could serve as a finer invariant separating non-isomorphic branch groups; the paper gives one such separation, and the sharp example at the threshold indicates the boundary is exactly where non-rigidity lives.
- Going beyond the paper: the first-order definability results imply that the model-theoretic type of a weakly branch group records its structure graph and, in the rigid case, its level-stabilizer filtration; this may allow elementary equivalence to detect dynamical data such as monodromy actions, a direction the paper opens but does not develop.
- Going beyond the paper: the counterexamples do not obviously disturb the arithmetic motivation behind Boston's conjecture, because the paper recalls that positive-dimensional subgroups of $W_p$ still satisfy the generalized $p$-adic representation expectation; a testable next step is whether deleted-level rigidity can be used to force zero-dimensionality in the Galois representations arising in th
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The paper develops tools for studying weakly branch actions on spherically homogeneous rooted trees: it extends Wilson's structure graph to weakly branch groups, proves first-order definability of the congruence topology and the structure graph, gives a characterization of rigidity in terms of T-filtrations, and shows equivalence between rigidity of a group and its congruence completion. For fractal groups of p-adic automorphisms, it gives a complete rigidity criterion and relates rigidity to Hausdorff dimension. The main application is a disproof of Boston's conjecture: the author claims that the closures of the just-infinite branch groups G_n constructed in his earlier work admit no positive-dimensional embedding into W_p, using a newly proved rigidity theorem for actions on trees obtained by deletion of levels.
Significance. If the main theorems are correct, the paper resolves a 25-year-old conjecture and provides substantial new structural tools. The extension of the structure graph to weakly branch groups, the rigidity criterion in Theorem 3, the fractal characterization in Theorem 5, and the first connection between Hausdorff dimension and rigidity (Corollary 6) are significant contributions. The proof of Theorem 7, if fully justified, would show that the zero-dimensional just-infinite branch pro-p groups constructed in [20] indeed violate Boston's conjecture. The manuscript is generally careful and contains detailed arguments, and the new rigidity arguments in Section 6 appear coherent. However, the disproof rests on one unsupported assertion about non-branch embeddings and on several implicit technical steps that need clarification before the central claim can be accepted.
major comments (3)
- [Section 1 and Section 6.4] The disproof of Boston's conjecture requires showing that every embedding of G_n into W_p has zero-dimensional closure, not only those whose images are branch. The manuscript states in Section 1 that 'non-branch just-infinite pro-p subgroups of Wp are known to be zero-dimensional', but no reference or proof is given. This assertion is load-bearing: Theorem 7 and Eq. (6.5) only control branch actions, and if a non-branch just-infinite pro-p subgroup of W_p admitted a positive-dimensional embedding, the conclusion that each G_n is a counterexample would not follow. Please provide a precise citation or a proof of this assertion.
- [Theorem 6.4 proof] The step 'If Hu ≥ stτn+|u|(w) ... then H ≥ stτn(uw)' is stated to follow from Lemma 5.1 and Lemma 5.2, but the implication is not immediate. One needs a kernel argument: the kernel of the section map φ_u on St(u) is contained in St(w_k) because w_k is below u, so a lift of a section in St(w) can be adjusted by an element of H ∩ St(w_k) to obtain the full preimage in H ∩ St(uw). This argument is not written and is essential for the induction producing FTn = Sτn. Please expand this step.
- [Lemma 6.3 proof] The equality stρn(w) = ker φ_i|Stρn(tn1) relies on the assertion that every non-trivial element of A_{n+1} moves every vertex at level t_{n+1}^1. This is stated without proof or citation. The equality is used to derive Eq. (6.3), which is essential for the dichotomy and the subsequent index computation. Please justify this claim directly from the definition of A_{n+1} or supply a reference.
minor comments (6)
- [Page 1] The running title contains a typo: 'WEAKL Y BRANCH' should read 'WEAKLY BRANCH'.
- [References] Reference [36] spells 'Apects'; it should be 'Aspects'.
- [Proof of Theorem 4] The line 'ristH(v) = H ∩ rist(v) ≤ H ∩ rist(v) = ristH(v)' is garbled, presumably missing overlines; please rewrite the closure argument clearly.
- [Proof of Theorem 7] The notation hdim_{Wp}(χn(Gn)) is used even though χn(Gn) may not be closed; the Hausdorff dimension is defined for closed subgroups. Please write hdim_{Wp}(\overline{χn(Gn)}) or clarify that the same formula computes the dimension of the closure.
- [Lemma 6.2] The notation eAn for \tilde A_n is confusing, especially because H1 is initially defined as a subgroup of G_n/St(tn1) = A_n and later used as a subgroup of \tilde A_n. Please spell out the identification H1 ≤ \tilde A_n explicitly and use \tilde A_n consistently.
- [Section 5.4] In the definition of s_n(G), the expression 'p log_p |StG(n − 1) : StG(n)| − log_p |StG(n) : StG(n + 1)|' should be parenthesized as p·log_p(...) to avoid ambiguity.
Circularity Check
No circular step found: Theorem 7's reduction via Eq. (6.5) is a genuine rigidity argument; reliance on [20] is independent prior work, and the uncited 'known' claim on non-branch embeddings is a correctness gap, not a circularity.
full rationale
Walking the derivation chain, the central disproof (Theorem 7) is not circular in the rubric sense. The new content is Theorem 6.4, Tn-rigidity of Gn, proved from Proposition 6.1 and Lemmas 6.2–6.3; the final step compares an arbitrary branch action χn on Tp with the distinguished action ρn via the induced action on Tn. Equation (6.5) is a consequence of conjugation in Aut Tn, not a definitional identity, and the inequality hdimWp(χn(Gn)) ≤ liminf along the deleted levels is a standard subsequence argument. The facts that Gn is just-infinite branch and that the distinguished embedding has zero Hausdorff dimension are imported from the author's prior paper [20, Props. 6.11, 6.12], as is the generating-function formula Theorem 5.6; these are parameter-free published theorems with stated assumptions, so under the rubric they are independent support, not circularity. I do flag, as a non-circular correctness gap, the introduction's uncited assertion 'Since non-branch just-infinite pro-p subgroups of Wp are known to be zero-dimensional', on which the treatment of non-branch embeddings in Theorem 7 depends; this is an omitted proof/reference, not a reduction of the conclusion to the assumptions.
Assumptions & free parameters
assumptions (4)
- domain assumption The groups G_n from [20] are just-infinite branch pro-p groups whose closure in W_p has Hausdorff dimension zero (Prop 6.1 and 6.12 of [20]).
- domain assumption The Hausdorff dimension generating function result: for self-similar G ≤ W_p, hdim_Wp(G) = 1 - S_G(1/p), with s_n(G) non-negative (Theorem B of [20]).
- domain assumption Non-branch just-infinite pro-p subgroups of W_p have zero Hausdorff dimension.
- standard math Standard ZFC and group theory; basic properties of profinite groups, trees, Hausdorff dimension, and first-order logic.
Cite this review
Pith. "Pith review of Weakly branch actions: first-order theory, rigidity and Boston's conjecture." pith.science (2026). https://pith.science/paper/C4X7TY5G
@misc{pith2026250722507,
author = {Pith},
title = {Pith review of: Weakly branch actions: first-order theory, rigidity and Boston's conjecture},
year = {2026},
howpublished = {\url{https://pith.science/paper/C4X7TY5G}},
note = {Machine review of arXiv:2507.22507}
}
abstract
We disprove a well-known conjecture of Boston (2000), which claims that a just-infinite pro-$p$ group is branch if and only if it admits a positive-dimensional embedding in the group of $p$-adic automorphisms. This is obtained as a result of a comprehensive study of the rigidity of branch actions. Firstly, we generalize the notion of the structure graph, introduced by Wilson in 2000, to weakly branch groups and use it to prove several results on the first-order theory of weakly branch groups, extending previous results of Wilson on branch groups. Secondly, we completely characterize the rigidity of weakly branch and branch actions on arbitrary spherically homogeneous rooted trees, extending previous partial results (for branch actions) by Hardy, Garrido, Grigorchuk and Wilson. Moreover, we prove that rigidity of a weakly branch group is equivalent to rigidity of its closure in the full automorphism group. Thirdly, we extend greatly the sufficient conditions $(*)$ and $(**)$ of Grigorchuk and Wilson, which leads to a complete and very easy-to-check characterization of the rigidity of the weakly branch actions of a fractal group of $p$-adic automorphisms. We further establish the first connection in the literature between the Hausdorff dimension of a weakly branch action and its rigidity. Lastly, we put everything together to show that the zero-dimensional just-infinite branch pro-$p$ groups introduced recently by the author admit rigid branch actions on a tree obtained by deletion of levels. This, together with previous results of the author, shows that these groups are indeed counterexamples to the aforementioned conjecture of Boston.
Figures
Forward citations
Cited by 2 Pith papers
-
Automorphism-invariant refinements of weakly branch actions via overlap functions
For every finitely generated weakly branch action on a rooted tree there is a canonical refinement tree on which the automorphism group acts weakly branch and equals the normalizer of the group.
-
Groups of finite type: classification and structural properties
For many groups of finite type, topological finite generation, just-infiniteness and strong completeness are equivalent, and new algorithms classify the groups up to isomorphism on binary and ternary trees.
Reference graph
Works this paper leans on
-
[20]
Fari˜ na-Asategui, Restricted Hausdorff spectra of q-adic automorphisms, Adv
J. Fari˜ na-Asategui, Restricted Hausdorff spectra of q-adic automorphisms, Adv. Math. 472 (2025), 110294
work page 2025
-
[1]
Ab´ ert, Group laws and free subgroups in topological groups, Bull
M. Ab´ ert, Group laws and free subgroups in topological groups, Bull. Lond. Math. Soc. 37 (2005), 525–534
work page 2005
-
[2]
M. Ab´ ert and B. Vir´ ag, Dimension and randomness in groups acting on rooted trees,J. Amer. Math. Soc. 18 (2005), 157–192
work page 2005
-
[3]
O. Adams and T. Hyde, Profinite iterated monodromy groups of unicritical polynomials, arXiv preprint: 2504.13028
-
[4]
Y. Barnea and A. Shalev, Hausdorff dimension, pro- p groups, and Kac-Moody algebras, Trans. Amer. Math. Soc. 349 (1997), 5073–5091
work page 1997
-
[5]
Bartholdi, Branch rings, thinned rings, tree enveloping rings, Israel J
L. Bartholdi, Branch rings, thinned rings, tree enveloping rings, Israel J. Math. 158 (2006), 93–139
work page 2006
-
[6]
L. Bartholdi and V. Nekrashevych, Iterated monodromy groups of quadratic polynomials, I, Groups Geom. Dyn. 2 (2008), 309–336
work page 2008
-
[7]
L. Bartholdi and V. Nekrashevych, Thurston equivalence of topological polynomials, Acta Math. 197 (2006), 1–51
work page 2006
Show all 57 references
-
[8]
Bartholdi and B
L. Bartholdi and B. Vir´ ag, Amenability via random walks, Duke math. J. 130 (1) (2005), 39–56
2005
-
[9]
I. V. Bondarenko and I. O. Samoilovych, On finite generation of self-similar groups of finite type, Internat. J. Algebra Comput. 23 (01) (2013), 69–79
2013
-
[10]
Boston, p-adic Galois representations and pro-p Galois groups, in: New Horizons in Pro-p Groups, Birkh¨ auser Boston, MA1, 2000
N. Boston, p-adic Galois representations and pro-p Galois groups, in: New Horizons in Pro-p Groups, Birkh¨ auser Boston, MA1, 2000
2000
-
[11]
Boston, Some cases of the Fontaine-Mazur conjecture, II, J
N. Boston, Some cases of the Fontaine-Mazur conjecture, II, J. Number Theory 75 (2)(1999), 161–169
1999
-
[12]
Bridy, R
A. Bridy, R. Jones, G. Kelsey, and R. Lodge, Iterated monodromy groups of rational functions and periodic points over finite fields, Math. Ann. 390(1) (2024), 439–475
2024
-
[13]
A. M. Brunner, S. Sidki and A. C. Vieira, A just-nonsolvable torsion-free group defined on the binary tree, J. Algebra 211 (1999), 99–114
1999
-
[14]
Calegari, Even Galois representations and the Fontaine-Mazur conjecture, Invent
F. Calegari, Even Galois representations and the Fontaine-Mazur conjecture, Invent. Math. 185 (2011), 1–16
2011
-
[15]
M. M. Day, Amenable semigroups, Illinois J. Math. 1 (1957), 509–544
1957
-
[16]
Di Domenico, G
E. Di Domenico, G. A. Fern´ andez-Alcober, M. Noce and A. Thillaisundaram, p-Basilica groups, Mediterr. J. Math. 19 (2022), 275
2022
-
[17]
Douady and J
A. Douady and J. H. Hubbard, A proof of Thurston’s topological characterization of rational functions, Acta Math. 171(2) (1993), 263–297
1993
-
[18]
Fari˜ na-Asategui, Arboreal representations of linear groups, arXiv preprint: 2506.12745
J. Fari˜ na-Asategui, Arboreal representations of linear groups, arXiv preprint: 2506.12745
-
[19]
Fari˜ na-Asategui, On a question of Ab´ ert and Vir´ ag, arXiv preprint: 2505.23142
J. Fari˜ na-Asategui, On a question of Ab´ ert and Vir´ ag, arXiv preprint: 2505.23142
-
[21]
Fari˜ na-Asategui and M
J. Fari˜ na-Asategui and M. E. Garciarena, The Hausdorff dimension of the generalized Brunner-Sidki-Vieira groups, arXiv preprint: 2403.16876
-
[22]
Fari˜ na-Asategui and R
J. Fari˜ na-Asategui and R. I. Grigorchuk, Branch actions and the structure lattice, Algebra Discrete Math. 38 (2) (2024), 215–232
2024
-
[23]
Fari˜ na-Asategui and S
J. Fari˜ na-Asategui and S. Radi, On the fixed-point proportion of self-similar groups, arXiv preprint: 2503.00185
-
[24]
G. A. Fern´ andez-Alcober and A. Zugadi-Reizabal, GGS-groups: order of congruence quotients and Hausdorff dimension, Trans. Amer. Math. Soc. 366 (4) (2014), 1993–2017
2014
-
[25]
Francoeur, On maximal subgroups of infinite index in branch and weakly branch groups, J
D. Francoeur, On maximal subgroups of infinite index in branch and weakly branch groups, J. Algebra 560 (2020), 818–851
2020
-
[26]
Fontaine and B
J.-M. Fontaine and B. Mazur, Geometric Galois representations, Elliptic Curves and Modular Forms, Proceedings of a conference held in Hong Kong, December 18–21 (1993), International Press, 1997. FIRST-ORDER THEORY, RIGIDITY AND BOSTON’S CONJECTURE 31
1993
-
[27]
Garrido, Aspects of branch groups , PhD thesis, University of Oxford, 2015
A. Garrido, Aspects of branch groups , PhD thesis, University of Oxford, 2015
2015
-
[28]
Garrido, On the congruence subgroup problem for branch groups, Israel J
A. Garrido, On the congruence subgroup problem for branch groups, Israel J. Math. 216 (2016), 1–13
2016
-
[29]
Garrido and J
A. Garrido and J. Uria-Albizuri, Pro- C congruence properties for groups of rooted tree auto- morphisms, Arch. Math. (Basel) 112 (2) (2019), 123–137
2019
-
[30]
R. I. Grigorchuk, Just infinite branch groups, in: New Horizons in pro-p Groups , Birkh¨ auser Boston, MA 1 (2000), 121–179
2000
-
[31]
R. I. Grigorchuk, On Burnside’s problem for periodic groups, Funktsional. Anal. i Prilozhen 14 (1) (1980), 53–54
1980
-
[32]
R. I. Grigorchuk, On Milnor’s problem on group growth, Soviet Math. Dokl. 28 (1983), 23–26
1983
-
[33]
R. I. Grigorchuk, Solved and unsolved problems around one group, in: Infinite groups: Geo- metric, Combinatorial and Dynamical Aspects , Progr. Math. 248, 2005
2005
-
[34]
R. I. Grigorchuk and J. S. Wilson, The uniqueness of the actions of certain branch groups on rooted trees, Geom. Dedicata 100 (1) (2003), 103–116
2003
-
[35]
Grigorchuk and A
R. Grigorchuk and A. ˙Zuk, On a torsion-free weakly branch group defined by a three state automaton, Internat. J. Algebra Comput. 12 (1) (2002), 223–246
2002
-
[36]
P. D. Hardy, Apects of abstract and profinite group theory , PhD thesis, University of Birm- ingham, 2002
2002
-
[37]
Jones, Iterated Galois towers, their associated martingales, and the p-adic Mandelbrot set, Compos
R. Jones, Iterated Galois towers, their associated martingales, and the p-adic Mandelbrot set, Compos. Math. 143 (5) (2007), 1108–1126
2007
-
[38]
J. Juul, P. Kurlberg, K. Madhu, and T. J. Tucker, Wreath products and proportions of periodic points, Int. Math. Res. Not. IMRN 13 (2016), 3944–3969
2016
-
[39]
Kisin, The Fontaine-Mazur conjecture for GL2, J
M. Kisin, The Fontaine-Mazur conjecture for GL2, J. Amer. Math. Soc. 22 (3) (2009), 641–690
2009
-
[40]
Milnor, Problem 5603, Amer
J. Milnor, Problem 5603, Amer. Math. Monthly 75 (1968), 685–686
1968
-
[41]
Nekrashevych, Self-Similar Groups
V. Nekrashevych, Self-Similar Groups. Mathematical Surveys and Monographs 117, Amer. Math. Soc. Providence, RI, 2005
2005
-
[42]
Nekrashevych and Y
V. Nekrashevych and Y. Lavreniuk, Rigidity of branch groups acting on rooted trees, Geom. Dedicata 89 (2002), 155–175
2002
-
[43]
R. W. K. Odoni, The Galois theory of iterates and composites of polynomials, Proc. Lond. Math. Soc. 51 (3) (1985), 385–414
1985
-
[44]
Pan, The Fontaine-Mazur conjecture in the residually reducible case, J
L. Pan, The Fontaine-Mazur conjecture in the residually reducible case, J. Amer. Math. Soc. 35 (4) (2022), 1031–1169
2022
-
[45]
J. M. Petschick, On conjugacy of GGS-groups, J. Group Theory 22 (2019), 347–358
2019
-
[46]
J. M. Petschick and K. Rajeev, On the Basilica operation, Groups Geom. Dyn. 17 (1)(2023), 331–384
2023
-
[47]
Radi, A family of level-transitive groups with positive fixed-point proportion and positive Hausdorff dimension, arXiv preprint: 2501.00515
S. Radi, A family of level-transitive groups with positive fixed-point proportion and positive Hausdorff dimension, arXiv preprint: 2501.00515
-
[48]
Rubin, On the reconstruction of topological spaces from their groups of homeomorphisms, Trans
M. Rubin, On the reconstruction of topological spaces from their groups of homeomorphisms, Trans. Amer. Math. Soc. 312 (2) (1989), 487–538
1989
-
[49]
Sidki and E
S. Sidki and E. F. da Silva, A family of just-nonsolvable torsion-free groups defined on n-ary trees, in: Atas da XVI Escola de Algebra, Brasilia Mat. Contemp. 21 (2001), 255–274
2001
-
[50]
C. M. Skinner and A. J. Wiles, Residually reducible representations and modular forms, Publ. Math. Inst. Hautes ´Etudes Sci. 89 (1999), 5–126
1999
-
[51]
Skipper and A
R. Skipper and A. Thillaisundaram, GGS-groups acting on trees of growing degrees,Commun. Algebra (2025), online first
2025
-
[52]
ˇSuni´ c, Hausdorff dimension in a family of self-similar groups,Geom
Z. ˇSuni´ c, Hausdorff dimension in a family of self-similar groups,Geom. Dedicata 124 (2007), 213–236
2007
-
[53]
Thillaisundaram and J
A. Thillaisundaram and J. Uria-Albizuri, The profinite completion of multi-EGS groups, J. Group Theory 24 (2021), 321–357
2021
-
[54]
J. S. Wilson, Groups with every proper quotient finite, Proc. Camb. Phil. Soc. 69 (1971), 373–391
1971
-
[55]
J. S. Wilson, On just infinite abstract and profinite groups, in:New Horizons in Pro-p Groups, Birkh¨ auser Boston, MA1, 2000
2000
-
[56]
J. S. Wilson, Structure theory for branch groups, in: Geometric and Homological Topics in Group Theory , London Math. Soc. Lecture Notes Series 358 Cambridge University Press, Cambridge, 2009. 32 JORGE F ARI ˜NA-ASATEGUI
2009
-
[57]
J. S. Wilson, The first-order theory of branch groups, J. Aust. Math. Soc. 102 (2017), 150– 158. Jorge F ari˜na-Asategui: Centre for Mathematical Sciences, Lund University, 223 62 Lund, Sweden – Department of Mathematics, University of the Basque Country UPV/EHU, 48080 Bilbao,...
2017
Reviewed August 6, 2026 · model on record in the stance chip above.
Discussion (0). Continue with ORCID to comment.