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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.

168,657 papers · 148 categories

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67133200266 · Jun 202019922001200920172026
48 results for GKM graphs

The paper studies quaternionic structures on GKM graphs and their relation to torus actions on quaternionic projective spaces.

problem Understanding quaternionic structures on GKM graphs and their implications for torus actions.
method Introducing quaternionic structures on GKM graphs and analyzing their properties in the context of torus actions.
result Abstract GKM graphs with specific 2-face structures correspond to torus actions on quaternionic projective spaces or Grassmannians.

Investigates conditions for GKM fiber bundles and realizability of fiber bundles of GKM graphs.

problem Conditions for GKM fiber bundles and realizability of fiber bundles of GKM graphs.
method Analysis of GKM graphs and fiber bundles, counterexamples, and classification of twist automorphisms.
result Realizability of fiber bundles of GKM graphs depends on the twist automorphism and can be decided in terms of the classification.

The equivariant cohomology ring of a GKM manifold is isomorphic to the cohomology ring of its GKM graph. In this paper we explore the implications of this fact for equivariant fiber bundles for which the total space and the base space are both GKM and derive a graph theoretical version of the Leray-Hirsch theorem. Then…

2008-06-22abs ↗pdf ↗

The aim of this paper is to give an upper bound for the dimension of a torus TT which acts on a GKM manifold MM effectively. In order to do that, we introduce a free abelian group of finite rank, denoted by A(Γ,α,)\mathcal{A}(Γ,α,\nabla), from an (abstract) (m,n)(m,n)-type GKM graph (Γ,α,)(Γ,α,\nabla). Here, an (m,n)(m,n)-type GKM …

2015-10-25abs ↗pdf ↗

We describe a generalization of GKM theory for actions of arbitrary compact connected Lie groups. To an action satisfying the non-abelian GKM conditions we attach a graph encoding the structure of the non-abelian 1-skeleton, i.e., the subspace of points with isotopy rank at most one less than the rank of the acting gro…

2012-08-28abs ↗pdf ↗

The study examines the independence of GKM manifolds and symmetric spaces.

problem Understanding the independence of isotropy weights in GKM manifolds.
method Using weighted graphs and properties of symmetric spaces, the study analyzes the independence of isotropy weights.
result The maximal independence of G/HG/H is 22, 33, or n=dimTn=\dim T, corresponding to symmetric spaces of rank >2>2.

Let T be a torus of dimension at least k and M a T-manifold. M is a GKM_k-manifold if the action is equivariantly formal, has only isolated fixed points, and any k weights of the isotropy representation in the fixed points are linearly independent. In this paper we compute the cohomology rings with real and integer coe…

2014-02-11abs ↗pdf ↗

Automorphisms of Hessenberg varieties are algebraic tori of dimension n-1.

problem Understanding the automorphisms of Hessenberg varieties.
method Analyzing the structure of automorphism groups of Hessenberg varieties.
result The reductive part of the identity component of the automorphism group of a connected Hessenberg variety is an algebraic torus of dimension n-1.

Let GG be a torus and MM a compact Hamiltonian GG-manifold with finite fixed point set MGM^G. If TT is a circle subgroup of GG with MG=MTM^G=M^T, the TT-moment map is a Morse function. We will show that the associated Morse stratification of MM by unstable manifolds gives one a canonical basis of KG(M)K_G(M). A key in…

2003-09-19abs ↗pdf ↗

The one-skeleton of a G-manifold M is the set of points p in M where dimGpdimG1\dim G_p \geq \dim G -1; and M is a GKM manifold if the dimension of this one-skeleton is 2. Goresky, Kottwitz and MacPherson show that for such a manifold this one-skeleton has the structure of a ``labeled" graph, (Γ,α)(Γ, α), and that the equivariant…

1999-03-09abs ↗pdf ↗

In this paper we study non-negatively curved and rationally elliptic GKM4_4 manifolds and orbifolds. We show that their rational cohomology rings are isomorphic to the rational cohomology of certain model orbifolds. These models are quotients of isometric actions of finite groups on non-negatively curved torus orbifol…

2018-02-16abs ↗pdf ↗

Let ΓΓ be a finite d-valent graph and G an n-dimensional torus. An ``action'' of G on ΓΓ is defined by a map, αα, which assigns to each oriented edge e of ΓΓ a one-dimensional representation of G (or, alternatively, a weight, αeα_e, in the weight lattice of G). For the assignment, eαee \to α_e, to be a schematic des…

2000-07-26abs ↗pdf ↗

We investigate the equivariant cohomology of the natural torus action on a K-contact manifold and its relation to the topology of the Reeb flow. Using the contact moment map, we show that the equivariant cohomology of this action is Cohen-Macaulay, which is a generalization of equivariant formality for torus actions wi…

2011-02-22abs ↗pdf ↗

Let MM be a symplectic manifold equipped with a Hamiltonian action of a torus TT. Let FF denote the fixed point set of the TT-action and let i:FMi:F\hookrightarrow M denote the inclusion. By a theorem of F. Kirwan \cite{K} the induced map i:HT(M)HT(F)i^*:H_T^*(M) \to H_T^*(F) in equivariant cohomology is an injection. We give …

1998-12-01abs ↗pdf ↗

The paper studies almost complex torus manifolds using graphs and Hirzebruch genera, proving properties of their fixed points and cohomology.

problem Understanding the fixed points and cohomology of almost complex torus manifolds.
method Using directed labeled multigraphs and Hirzebruch genera to encode and analyze the manifolds.
result Almost complex torus manifolds have positive Todd genus and at least n+1 fixed points.

Improved private learning for Littlestone classes with a doubly-exponential mistake bound.

problem Private learning of Littlestone classes with approximate differential privacy constraints.
method Combines refined interpretation of irreducibility technique, improved sparse selection algorithm, and Exponential Mechanism.
result Achieved a mistake bound of \(\tilde{O}(d^{9.5} \cdot \log(T))\) for online learning of Littlestone classes.

Line graph transformation aids graph isomorphism tests by excluding challenging graph properties.

problem Limited theoretical understanding of line graph transformation's impact on GNN models.
method Examined CFI and strongly regular graphs, showing line graph transformation helps WL tests distinguish these graphs.
result Line graph transformation aids WL tests in distinguishing challenging graph properties.

Proposes MGMN for end-to-end graph similarity learning.

problem Lack of cross-level interactions in graph similarity learning.
method Multi-level graph matching network (MGMN) combining node-graph matching and siamese graph neural networks.
result MGMN outperforms state-of-the-art models on graph-graph classification and regression tasks.

MxPool learns graph features from diverse graphs using a hierarchical structure.

problem Learning graph features from diverse graphs with varying properties and sizes.
method MxPool uses a multiplex structure with multiple graph convolution/pooling networks in a hierarchical learning structure.
result MxPool outperforms state-of-the-art methods on graph classification benchmarks.

Quasi-transitive graphs quasi-isometric to planar graphs can be upgraded to Cayley graphs.

problem Quasi-transitive graphs quasi-isometric to planar graphs need to be upgraded to Cayley graphs.
method Upgrading a planar graph to a Cayley graph.
result Quasi-transitive graphs quasi-isometric to planar graphs can be upgraded to Cayley graphs.

Characterizes graphs with leveled embeddings and introduces new graph invariants.

problem Understanding the properties of leveled embeddings in spatial graphs.
method Characterization of graphs with leveled embeddings, introduction of new invariants.
result Characterization of graphs with low level number and determination of specific invariants for complete graphs and complete bipartite graphs.

Two new methods improve graph embedding without needing a complete graph structure.

problem Graph autoencoders' performance depends on the adjacency matrix quality.
method BAGE and VBAGE: unsupervised graph embedding via adaptive graph learning.
result The methods expand GAEs' applicability to datasets without graph structure.

We define a pseudo-inverse for line graphs using linear integer programming.

problem Not all graphs have a corresponding root graph, making the line graph operation non-invertible.
method Propose a linear integer program to edit the smallest number of edges in the line graph to recover a root graph.
result The pseudo-inverse operation is well-behaved and works in practice as shown by empirical experiments.

Unified framework for graph coarsening using node features and graph matrices.

problem Dimensionality reduction of large graphs while preserving node features.
method Optimization-based framework that unifies graph learning and dimensionality reduction.
result The learned coarsened graph is ε-similar to the original graph, where ε is a small positive number.

PSimGNN partitions graphs into subgraphs for efficient graph similarity computation.

problem Efficiently compute graph similarity scores for large graphs.
method Graph partitioning followed by subgraph-level and node-level comparisons using a graph neural network.
result PSimGNN outperforms state-of-the-art methods in graph similarity computation tasks.

We present graph wavelet neural network (GWNN), a novel graph convolutional neural network (CNN), leveraging graph wavelet transform to address the shortcomings of previous spectral graph CNN methods that depend on graph Fourier transform. Different from graph Fourier transform, graph wavelet transform can be obtained …

2019-04-12abs ↗pdf ↗

Graph Convolutional Neural Networks (Graph CNNs) are generalizations of classical CNNs to handle graph data such as molecular data, point could and social networks. Current filters in graph CNNs are built for fixed and shared graph structure. However, for most real data, the graph structures varies in both size and con…

2018-01-10abs ↗pdf ↗

Graph Cascades rewire graphs to improve structure-aware learning.

problem Improving graph neural networks and transformers for structure-aware learning.
method Graph Cascades uses contagion-based diffusion processes to construct an auxiliary graph with reinforced edges.
result Graph Cascades improves node-classification benchmarks across various graph types.

CTGCN learns dynamic graph embeddings preserving both local and global graph structure.

problem Learning node representations for evolving graphs while preserving both local and global graph structure.
method CTGCN uses k-core based temporal graph convolutional network to learn dynamic graph embeddings.
result CTGCN outperforms existing methods in link prediction and structural role classification.