Research
On-device research index

arXiv research

A locally-built, LLM-digested index of recent arXiv papers in quant finance, geometry/topology, and statistical ML — keyword search served straight from SQLite on this machine.

168,694 papers · 148 categories

Trend · papers per month

82164245327 · Jun 202019922001200920172026
48 results for virtually free groups

The study shows exponential distortion in virtually special groups containing free subgroups.

problem Understanding distortion in virtually special groups containing free subgroups.
method Constructing examples of virtually special groups with finite rank free subgroups.
result Distortion functions grow like exp^k(x^m) and can be superexponential.

The paper constructs representations of flat virtual braids by free group automorphisms.

problem Representing flat virtual braids by automorphisms of free groups.
method Construction of representations of flat virtual braid groups FVBnFVB_n by automorphisms of free groups of rank 2n2n.
result Established conditions of faithfulness and properties of the kernel for n3n\ge3.

The paper extends Lipschitz metric isometries between Outer Spaces of virtually free groups.

problem Extending isometry properties of Lipschitz metric to virtually free groups.
method Analyzing finite-index subgroups and their covers, identifying folding paths, and using deformation retraction.
result Existence of candidates for Lipschitz distance and deformation retraction of spine.

New groups found that don't virtually algebraically fiber, related to mapping class group orbits.

problem Existence of finite orbits for higher Prym representations of the mapping class group.
method Study of surface-by-surface and surface-by-free groups.
result Existence of free-by-free and free-by-surface groups that do not algebraically fiber.

We show, using Wise's equitable sets criterion, that every tubular free by cyclic group acts freely on a CAT(0) cube complex. We also show that these groups have a finite index subgroup satisfying the strongest Tits alternative, which means that every subgroup either surjects a non abelian free group or is torsion free…

2015-10-20abs ↗pdf ↗

Proves incoherence of free-by-free and surface-by-free groups, solving two problems.

problem Proving incoherence of free-by-free and surface-by-free groups.
method Semidirect product construction and virtual algebraic fibering analysis.
result Proves incoherence of free-by-free and surface-by-free groups, answering a question posed by J. Hillman.

We study groups of some virtual knots with small number of crossings and prove that there is a virtual knot with long lower central series which, in particular, implies that there is a virtual knot with residually nilpotent group. This gives a possibility to construct invariants of virtual knots using quotients by term…

2018-11-23abs ↗pdf ↗

In this paper we generalize the notion of strongly poly-free group to a larger class of groups, we call them strongly poly-surface groups and prove that the Fibered Isomorphism Conjecture of Farrell and Jones corresponding to the stable topological pseudoisotopy functor is true for any virtually strongly poly-surface g…

2002-09-11abs ↗pdf ↗

A generalized Baumslag-Solitar group (GBS group) is a finitely generated group GG which acts on a tree with all edge and vertex stabilizers infinite cyclic. We show that Out(G) either contains non-abelian free groups or is virtually nilpotent of class at most 2. It has torsion only at finitely many primes. One may dec…

2005-11-03abs ↗pdf ↗

Using a probabilistic argument we show that the second bounded cohomology of an acylindrically hyperbolic group GG (e.g., a non-elementary hyperbolic or relatively hyperbolic group, non-exceptional mapping class group, Out(Fn){\rm Out}(F_n), \dots) embeds via the natural restriction maps into the inverse limit of the secon…

2017-01-03abs ↗pdf ↗

We study the structure of the virtual braid group. It is shown that the virtual braid group is a semi--direct product of the virtual pure braid group and the symmetric group. Also, it is shown that the virtual pure braid group is a semi--direct product of free groups. From these results we obtain a normal form of words…

2004-07-23abs ↗pdf ↗

The study establishes conditions for groups acting on polygonal complexes to contain virtually free subgroups.

problem Conditions for groups acting on polygonal complexes to contain virtually free subgroups.
method Analysis of links of polygonal complexes and conditions on their structure.
result Groups acting on polygonal complexes with certain link conditions contain virtually free subgroups.

The paper defines and analyzes configuration Lie groupoids and orbifold braid groups.

problem Understanding the structure and properties of orbifold braid groups.
method Definitions and proofs of fibration theorems, short exact sequences, and poly-virtually free structures.
result The pure orbifold braid groups have poly-virtually free structure, generalizing classical braid groups.

Study proves equality of LS-category and cohomological dimension for specific group homomorphisms.

problem Proving equality of LS-category and cohomological dimension for specific group homomorphisms.
method Analyzing epimorphisms and homomorphisms between specific types of almost nilpotent and virtually nilpotent groups.
result Equality of LS-category and cohomological dimension for specified group homomorphisms.

The geometric dimension for proper actions gd(G)\underline{\mathrm{gd}}(G) of a group GG is the minimal dimension of a classifying space for proper actions EG\underline{E}G. We construct for every integer r1r\geq 1, an example of a virtually torsion-free Gromov-hyperbolic group GG such that for every group ΓΓ which con…

2016-02-13abs ↗pdf ↗

Let ΓΓ be a connected, triangle-free, planar graph with at least five vertices that has no separating vertices or edges. If the graph ΓΓ is CFS\mathcal{CFS}, we prove that the right-angled Coxeter group GΓG_Γ is virtually a Seifert manifold group or virtually a graph manifold group and we give a complete quasi-isometr…

2017-12-04abs ↗pdf ↗

In this article, we investigate various properties of the pure virtual braid group PV_3. From its canonical presentation, we obtain a free product decomposition of PV_3. As a consequence, we show that PV_3 is residually torsion free nilpotent, which implies that the set of finite type invariants in the sense of Goussar…

2009-06-09abs ↗pdf ↗

We prove that the profinite completion of the fundamental group of a compact 3-manifold MM satisfies a Tits alternative: if a closed subgroup HH does not contain a free pro-pp subgroup for any pp, then HH is virtually soluble, and furthermore of a very particular form. In particular, the profinite completion of th…

2014-11-19abs ↗pdf ↗

The paper extends arithmetic quotient results to right-angled Artin groups.

problem Arithmetic quotients of automorphism groups of free groups and mapping class groups.
method Analogous methods to free groups and mapping class groups applied to right-angled Artin groups.
result New virtual arithmetic quotients of Aut(F_n) for n ≥ 4, containing nonabelian free groups.

We consider linear groups which do not contain unipotent elements of infinite order, which includes all linear groups in positive characteristic, and show that this class of groups has good properties which resemble those held by groups of non positive curvature and which do not hold for arbitrary characteristic zero l…

2017-03-16abs ↗pdf ↗

Based on a recently introduced by the author notion of {\em parity}, in the present paper we construct a sequence of invariants (indexed by natural numbers mm) of long virtual knots, valued in certain simply-defined group G~m{\tilde G}_{m} (the Cayley graphs of these groups are represented by grids in the (m+1)(m+1)-space…

2010-04-25abs ↗pdf ↗

We present the results of computer experiments suggesting that the probability that a random multiword in a free group is virtually geometric decays to zero exponentially quickly in the length of the multiword. We then prove this fact.

2014-07-29abs ↗pdf ↗

Paper studies pure virtual twin groups and their automorphisms.

problem Understanding the structure and automorphisms of pure virtual twin groups.
method Analyzes stable isotopy classes of immersed circles on surfaces, extending classical knot theory.
result Proves PVTnPVT_n is an irreducible right-angled Artin group with trivial center and gives its precise presentation.

We give a technical result that implies a straightforward necessary and sufficient conditions for a graph of groups with virtually cyclic edge groups to be one ended. For arbitrary graphs of groups, we show that if their fundamental group is not one-ended, then we can blow up vertex groups to graphs of groups with simp…

2014-03-25abs ↗pdf ↗

The study shows subgroup separability conditions for specific groups.

problem Conditions for subgroup separability in free-by-cyclic and deficiency 1 groups.
method Analyzes polynomially growing monodromy and asymptotic probability of random groups.
result Random deficiency 1 groups are not subgroup separable with positive probability.

Gordon and Wilton recently proved that the double D of a free group F amalgamated along a cyclic subgroup C of F contains a surface group if a generator w of C satisfies a certain 3-manifold theoretic condition, called virtually geometricity. Wilton and the author defined the polygonality of w which also guarantees the…

2009-10-27abs ↗pdf ↗

The study proves conjecture for specific Artin groups.

problem Proving conjecture about Artin groups' properties.
method Analyzing Artin groups associated to triangle-free graphs and cones over square-free bipartite graphs.
result Proves conjecture for specific Artin groups.

We show that for groups acting acylindrically on simplicial trees the KK- and LL-theoretic Farrell-Jones Conjecture relative to the family of subgroups consisting of virtually cyclic subgroups and all subconjugates of vertex stabilisers holds. As an application, for amalgamated free products acting acylindrically on …

2017-04-19abs ↗pdf ↗

The automorphisms of free groups with boundaries form a family of groups A_{n,k} closely related to mapping class groups, with the standard automorphisms of free groups as A_{n,0} and (essentially) the symmetric automorphisms of free groups as A_{0,k}. We construct a contractible space L_{n,k} on which A_{n,k} acts wit…

2004-02-11abs ↗pdf ↗

A fixed point theorem is proved for inverse transducers, leading to an automata-theoretic proof of the fixed point subgroup of an endomorphism of a finitely generated virtually free group being finitely generated. If the endomorphism is uniformly continuous for the hyperbolic metric, it is proved that the set of regula…

2012-03-07abs ↗pdf ↗

The study shows that certain groups can be uniquely identified by their finite abelian summands.

problem Identifying groups based on their finite abelian summands.
method Analyzing hyperbolic groups as graphs of free groups with cyclic edge groups.
result Free products of free and surface groups are profinitely rigid.

We prove that all atoroidal automorphisms of Out(FN)Out(F_N) act on the space of projectivized geodesic currents with generalized north-south dynamics. As an application, we produce new examples of non virtually cyclic, free and purely atoroidal subgroups of Out(FN)Out(F_N) such that the corresponding free group extension is hyp…

2017-11-21abs ↗pdf ↗