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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.

168,657 papers · 148 categories

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101202303404 · May 202619922001200920172026
48 results for group constructions

Riley "defined" the Heckoid groups for 2-bridge links as Kleinian groups, with nontrivial torsion, generated by two parabolic transformations, and he constructed an infinite family of epimorphisms from 2-bridge link groups onto Heckoid groups. In this paper, we make Riley's definition explicit, and give a systematic co…

2012-05-21abs ↗pdf ↗

Alternative construction of Rumin complex on Lie groups.

problem Constructing Rumin complex on homogeneous nilpotent Lie groups.
method Using ideas from parabolic geometry, an alternative construction to the classical one on Carnot groups.
result Explicit computations for the Engel group using the new approach.

We present a nonstandard hull construction for locally uniform groups in a spirit similar to Luxembourg's construction of the nonstandard hull of a uniform space. Our nonstandard hull is a local group rather than a global group. We investigate how this construction varies as one changes the family of pseudometrics used…

2012-03-29abs ↗pdf ↗

Geometrically constructs Virasoro-Bott group from circle diffeomorphisms.

problem Constructing the Virasoro-Bott group from circle diffeomorphisms.
method Analogous to loop group construction, using disc diffeomorphisms with special boundary conditions.
result Identifies Virasoro-Bott group as a quotient of disc diffeomorphisms with identified Lie algebra.

We construct uncountably many discrete groups of type FPFP; in particular we construct groups of type FPFP that do not embed in any finitely presented group. We compute the ordinary, 2\ell^2- and compactly-supported cohomology of these groups. For each n4n\geq 4 we construct a closed aspherical nn-manifold that admit…

2015-12-21abs ↗pdf ↗

In Part I of this series of papers, we made Riley's definition of Heckoid groups for 2-bridge links explicit, and gave a systematic construction of epimorphisms from 2-bridge link groups onto Heckoid groups, generalizing Riley's construction. In this paper, we give a complete characterization of upper-meridian-pair-pre…

2012-06-03abs ↗pdf ↗

We give an algebro-geometric construction of some of the non-arithmetic ball quotients constructed by the author, Parker and Paupert. The new construction reveals a relationship between the corresponding orbifold fundamental groups and the automorphism group of the Klein quartic, and also with groups constructed by Bar…

2016-05-12abs ↗pdf ↗

Sapir, Birget and Rips showed how to construct groups from Turing machines. To achieve such a construction they introduced the notion of S-machine. Then considering a simplified S-machine Sapir and Olshanskii showed how to construct a group such that each of its asymptotic cone is non-simply connected. Still using the …

2014-01-21abs ↗pdf ↗

Constructs generalized Frobenius manifolds for specific Weyl groups.

problem Creating structures for orbit spaces of Weyl groups.
method Applying a previously established construction method to specific Weyl groups.
result Generalized Frobenius manifold structures constructed for A,B,CA_\ell, B_\ell, C_\ell and DD_\ell.

In this paper we construct the Differential calculus on the Hopf Group Coalgebra introduced by Turaev [10]. We proved that the concepts introduced by S.L.Woronowicz in constructing Differential calculus on Hopf Compact Matrix Pseudogroups (Quantum Groups)[7] can be adapted to serve again in our construction.

2005-07-25abs ↗pdf ↗

Paper connects algebraic and analytic methods for braid group representations.

problem Constructing representations of braid groups using algebraic and analytic approaches.
method Katz-Long-Moody construction and multiplicative middle convolution for KZ-type equations.
result Multiplicative middle convolution preserves unitarity and provides an algorithm to determine the signature of a Hermitian matrix.

New subgroups of mapping class groups constructed for infinite-type surfaces.

problem Constructing new subgroups of mapping class groups for infinite-type surfaces.
method Utilization of special homeomorphisms called shift maps and multipush maps.
result Countably (and uncountably in certain cases) many non-conjugate embeddings of subgroups into mapping class groups.

We define a 3-loop group Ω3GΩ^3G as a subgroup of smooth maps from a 3-ball to a Lie group GG, and then construct a 2-group based on an automorphic action on the Mickelsson-Faddeev extension of Ω3GΩ^3G. In this we follow the strategy of Murray et al., who earlier described a similar construction in one dimension. The th…

2018-09-29abs ↗pdf ↗

New method constructs equivariant neural networks for arbitrary matrix groups.

problem Challenges in constructing equivariant neural networks for complex groups.
method Completely general algorithm for solving equivariant layers of matrix groups.
result Constructs multilayer perceptrons equivariant to multiple groups including O(1,3), O(5), Sp(n), and Rubik's cube group.

This paper explores links from Thompson's group conjugacy classes.

problem Understanding the relationship between Thompson's group conjugacy classes and links.
method Using Jones's construction to link elements of FF to unoriented links.
result Found sequences of elements from distinct conjugacy classes yielding specific links.

Paper connects Stokes phenomena to quantum groups and Poisson-Lie groups.

problem Analyse Stokes phenomena in Poisson-Lie groups and quantum groups.
method Use Ug-valued Stokes phenomena to construct quantum group U_hg and relate it to Poisson-Lie group G*.
result Show that Ug-valued Stokes phenomena can be obtained as a semiclassical limit of the KZ associator.

We construct an embedding of any right-angled Artin group G(Δ)G(Δ) defined by a graph ΔΔ into a graph braid group. The number of strands required for the braid group is equal to the chromatic number of ΔΔ. This construction yields an example of a hyperbolic surface subgroup embedded in a two strand planar graph braid g…

2005-06-13abs ↗pdf ↗

New method constructs explicit pp-harmonic functions on Lie groups.

problem Constructing proper pp-harmonic functions on Lie groups.
method Employing complex isoparametric functions to devise a general method.
result First explicit proper pp-harmonic functions on RmRn\mathbb{R}^m \ltimes \mathbb{R}^n and RmH2n+1\mathbb{R}^m \ltimes \mathrm{H}^{2n+1}.

The article constructs Fuchsian Schottky groups with conformal boundaries.

problem Creating generalized Schottky groups with specific properties.
method Developed Fuchsian Schottky groups by including orientation-reversing isometries.
result Decomposed compact core of conformally compact Riemann surfaces into pairs of pants.

The paper constructs infinite rank summands in diffeomorphism groups via Seiberg-Witten theory.

problem Constructing infinite rank summands in diffeomorphism groups.
method Using Seiberg-Witten theory, the paper constructs spherical families and computes invariants.
result Infinite rank summands in homotopy and homology groups of diffeomorphism groups.

Proves HNN extensions of nilpotent groups are left-orderable, constructs non-left-orderable examples.

problem Characterizing left-orderability in HNN extensions of groups.
method Analyzes HNN extensions of torsion-free nilpotent groups and left-orderable groups.
result Constructs examples of non-left-orderable HNN extensions of left-orderable groups.

Given a family of groups admitting a braided monoidal structure (satisfying mild assumptions) we construct a family of spaces on which the groups act and whose connectivity yields, via a classical argument of Quillen, homological stability for the family of groups. We show that stability also holds with both polynomial…

2014-09-11abs ↗pdf ↗

We describe how an Ore category with a Garside family can be used to construct a classifying space for its fundamental group(s). The construction simultaneously generalizes Brady's classifying space for braid groups and the Stein--Farley complexes used for various relatives of Thompson's groups. It recovers the fact th…

2017-10-09abs ↗pdf ↗

We construct finite volume hyperbolic manifolds with large symmetry groups. The construction makes use of the presentations of finite Coxeter groups provided by Barot and Marsh and involves mutations of quivers and diagrams defined in the theory of cluster algebras. We generalize our construction by assigning to every …

2014-09-11abs ↗pdf ↗

The study restricts groups in graph of groups structures.

problem Realizing groups as fundamental groups of graph of groups with restricted vertex groups.
method Analyzes restrictions on groups that can be realized and applies to manifold construction.
result Places constraints on groups that can be realized in graph of groups structures.

The Hessian geometry is the real analogue of the Kähler one. Sasakian geometry is an odd-dimensional counterpart of the Kähler geometry. In the paper, we study the connection between projective Hessian and Sasakian manifolds analogous to the one between Hessian and Kähler manifolds. In particular, we construct a Sasaki…

2018-03-07abs ↗pdf ↗

We construct quasi-isometric embeddings from right-angled Artin groups into the outer automorphism group of a free group. These homomorphisms are in analogy with those constructed in \cite{CLM}, where the target group is the mapping class group of a surface. Toward this goal, we develop tools in the free group setting …

2013-03-27abs ↗pdf ↗

In this paper we address the question of the existence of a model for the string 2-group as a strict Lie-2-group using the free loop group LSpinLSpin (or more generally LGLG for compact simple simply-connected Lie groups GG). Baez-Crans-Stevenson-Schreiber constructed a model for the string 2-group using a based loop gro…

2017-02-06abs ↗pdf ↗

For every finitely generated abelian group G, we construct an irreducible open 3-manifold MGM_{G} whose end set is homeomorphic to a Cantor set and with end homogeneity group of MGM_{G} isomorphic to G. The end homogeneity group is the group of self-homeomorphisms of the end set that extend to homeomorphisms of the 3-m…

2013-07-30abs ↗pdf ↗

The twist construction is a geometric model of T-duality that includes constructions of nilmanifolds from tori. This paper shows how one-dimensional foliations on manifolds may be used in a shear construction, which in algebraic form builds certain solvable Lie groups from Abelian ones. We discuss other examples of geo…

2015-05-31abs ↗pdf ↗

New method constructs proper affine actions of groups in higher dimensions.

problem Finding proper affine actions of discrete groups in higher-dimensional spaces.
method Higher strip deformations and Margulis invariant for properness.
result Affine actions of convex cocompact groups and virtually free groups are constructed properly.