The paper examines complex and para-complex structures on pseudo-Riemannian spheres.
problem Exploring non-integrable Cayley structures on pseudo-Riemannian spheres.
method Study of Cayley structures on six-dimensional pseudo-Riemannian spheres.
result Existence of complex and para-complex structures on pseudospheres.
Study of Cayley structures linked to differential equations.
problem Understanding Cayley structures and their differential equations.
method Defined Cayley structures, introduced extensions, solved equivalence problem.
result Found fundamental invariants and examples of Cayley structures.
Introduces Lorentzian Cayley form solving geometric puzzle.
problem Solving geometric puzzle in 4D Lorentzian geometry.
method Introduces complex Cayley forms and Lorentzian Cayley form.
result Lorentzian Cayley form solves geometric puzzle.
The Cayley graph of quandles reveals structural properties and is studied for various classes.
problem Investigating structural properties of Cayley graphs of quandles.
method Analyzing Cayley graphs for different quandle classes and proving properties.
result Connected components of Cayley graphs of Alexander quandles correspond to cosets of specific subgroups.
We construct a Kaehler structure on the punctured cotangent bundle of the Cayley projective plane whose Kaehler form coincides with the natural symplectic form on the cotangent bundle and we show that the geodesic flow action is holomorphic and is expressed in a quite explicit form. We also give an embedding of the pun…
Let M be an 8-manifold with a Spin(7)-structure. We first show that closed Cayley submanifolds of M form a smooth moduli space for a generic Spin(7)-structure. Then we study the deformations of a compact, connected Cayley submanifold X of M with non-empty boundary contained in a given submanifold W of M such that X and…
Study shows only two topological configurations for Spin(7)-manifold fibrations, ruling out smooth Cayley fibrations.
problem Understanding smooth fibrations of compact Spin(7)-manifolds by Cayley submanifolds.
method Geometric and topological constraints from Spin(7)-structure, spinnability criterion, gauge-theoretic input.
result Rules out smooth Cayley fibrations on all known compact torsion-free Spin(7)-manifolds.
This paper shows that, away from 6, the kernel of the Witten genus is precisely the ideal consisting of (bordism classes of) Cayley plane bundles with connected structure group, but only after restricting the Witten genus to string bordism. It does so by showing that the divisibility properties of Cayley plane bundle c…
Researchers found a Calabi-Yau structure and constructed a Bargmann type transformation on the Cayley projective plane.
problem Existence of Calabi-Yau structure and construction of Bargmann type transformation.
method Pairing of polarizations, natural Lagrangian foliation, and Kähler structure.
result Quantization of geodesic flow through elliptic Fourier integral operators.
Study of lamplighter group's Cayley graph spectrum and random Schrödinger operators.
problem Characterize the spectrum of Cayley graphs of the lamplighter group.
method Careful study of spectral properties of a one-parametric family of convolution operators on the lamplighter group.
result The spectrum of the discrete Laplacian on the Cayley graph of the lamplighter group is a union of an interval and a countable set of isolated points.
On realizations of the Lie groups $ G_{2,\boldmath\scriptstyle{H}},F_{4,\boldmath\scriptstyle{H}},E_{6,\boldmath\scriptstyle{H}},E_{7,\boldmath\scriptstyle{H}},E_{8,\boldmath\scriptstyle{H}} $, second editionmath.DG The paper examines alternative definitions of exceptional Lie groups using quaternion numbers.
problem Defining exceptional Lie groups using quaternion numbers.
method Replacing Cayley algebra with quaternion numbers to define the groups.
result Determined the structure of the new Lie groups.
The paper studies the graph geometry of finite groups, creating a dataset and analyzing its properties.
problem Understanding how group-theoretic structure is reflected in Cayley graph observables.
method Construction of a dataset of Cayley graphs for groups of order up to 767, analysis of graph statistics, and comparison of model performance.
result Graph statistics are highly informative for predicting group properties, and GNNs can recover substantial structural signal.
Spin(7) geometry linked to multisymplectic geometry.
problem Understanding Spin(7) structures through multisymplectic geometry.
method Utilized Spin(7) identities to prove non-degeneracy of Cayley four-form in multisymplectic context.
result Spin(7) geometry is a special case of multisymplectic geometry.
This paper explores the geometric and topological properties of Poncelet porism for triangles.
problem Investigating the differential-geometric and topological properties of the Cayley condition in Poncelet porism for triangles.
method Demonstrated that the Cayley set is a smooth, connected, 9-dimensional complex manifold. Analyzed its structure through moduli spaces and fiber bundles.
result The Cayley set is a smooth, connected, 9-dimensional complex manifold.
We study the deformations of an asymptotically cylindrical Cayley submanifold inside an asymptotically cylindrical Spin(7)-manifold. We prove an index formula for the operator of Dirac type that arises as the linearisation of the deformation map and show that if the Spin(7)-structure is generic, then there are no obstr…
Investigates second-order conditions for Cayley forms in eight dimensions.
problem Natural conditions for Cayley forms in eight dimensions.
method Linear and non-linear completion of Lagrangians, parametrization of intrinsic torsion, construction of action functional.
result Two-parameter family of diffeomorphism-invariant Lagrangians, leading to Einstein equations.
Deformations of singular Cayley submanifolds studied.
problem Constructing fibrations of compact Spin(7) manifolds.
method Deformation theory of conically singular and asymptotically conical Cayley submanifolds.
result Detailed description of the deformation theory.
On realizations of the complex Lie groups (F4,R)C,(E6,R)C,(E7,R)C,(E8,R)C and those compact real forms F4,R,E6,R,E7,R,E8,Rmath.DG The paper explores alternative definitions of complex Lie groups using real numbers.
problem Defining complex Lie groups using real numbers.
method Replacing Cayley algebra with real numbers to define groups.
result Determined the structure of complex and compact Lie groups.
New formulas for mean curvature of submanifolds in geometries with torsion.
problem Characterizing submanifolds in geometries with intrinsic torsion.
method Deriving formulas for mean curvature of associative, coassociative, and Cayley submanifolds.
result New obstructions to the local existence of coassociative 4-folds in G2-structures with torsion.
In this article we study the deformation theory of conically singular Cayley submanifolds. In particular, we prove a result on the expected dimension of a moduli space of Cayley deformations of a conically singular Cayley submanifold. Moreover, when the Cayley submanifold is a two-dimensional complex submanifold of a C…
Desingularizes conically singular Cayley submanifolds.
problem Constructing fibrations of compact Spin(7) manifolds by Cayley submanifolds.
method Desingularization through gluing rescaled asymptotically conical submanifolds.
result Conically singular Cayley submanifolds can be desingularized.
The study embeds infinite-dimensional geometric structures in Cayley graphs.
problem Embedding infinite-dimensional structures in finite Cayley graphs.
method Examples of groups and generating sets, quasi-isometric embeddings, subsurface projections.
result Cayley graphs contain quasi-isometric copies of Zm for all m≥1. In this paper we introduce the area of 2-ruled 4-folds in R^n (n=7 or 8), that is, submanifolds M of R^n that admit a fibration over some 2-fold Sigma such that each fibre is an affine 2-plane in R^n. This is motivated by the paper math.DG/0012060 by Joyce on ruled special Lagrangian 3-folds in C^3 and the work of the …
Third in a series, this paper constructs non-trivial Cayley fibrations with conical singularities.
problem Constructing non-trivial Cayley fibrations with conical singularities.
method Using gluing methods and stability results for weak and usual fibrations.
result Construction of examples of Cayley fibrations on twisted connected sum G2 manifolds. The study examines discrete curvature notions on Cayley graphs of certain groups.
problem Understanding curvature in discrete settings for various groups.
method Introduced Right Angled Artin-Coxeter Hybrids (RAACHs) and derived curvatures of Cayley graphs.
result Addition of relators does not decrease weighted curvatures of Cayley graphs.
Study Cayley fibrations on Bryant-Salamon Spin(7) manifolds.
problem Investigate Cayley fibrations on specific Spin(7) manifolds. method Analyze invariant Cayley fibrations for each SU(2) action. result Explicitly describe the fibres of Cayley fibrations.
Efficiently optimizes CNN and RNN parameters on Stiefel manifold.
problem Computational expense in optimizing orthonormal matrices on Stiefel manifold.
method Cayley transform for efficient retraction and vector transport on Stiefel manifold.
result Cayley SGD and ADAM achieve faster convergence and less training time.
The paper explores connections between quaternionic and Cayley calibrations in dimensions 8 and 16.
problem Exploring connections between quaternionic and Cayley calibrations in dimensions 8 and 16.
method Starting from collections of 'Kähler 2-forms', the paper constructs canonical 4-forms and calibrated 4-planes in dimensions 8 and 16.
result Explicit formulas for canonical 4-forms ΦSpin(8) and ΦSpin(7)U(1) are derived, and their calibrated 4-planes are characterized. Given a Kaehler manifold of complex dimension 4, we consider submanifolds of (real) dimension 4, whose Kaehler angles coincide. We call these submanifolds Cayley. We investigate some of their basic properties, and prove that (a) if the ambient manifold is a Calabi-Yau, the minimal Cayley submanifolds are just the Cayle…
Eastwood and Ezhov generalized the Cayley surface to the Cayley hypersurface in each dimension, proved some characteristic properties of the Cayley hypersurface and conjectured that a homogeneous hypersurface in affine space satisfying these properties must be the Cayley hypersurface. We will prove this conjecture when…
The study introduces Cayley--Abels--Rosendal graphs for Polish groups.
problem Understanding the structure of Polish groups through graph theory.
method Developing Cayley--Abels--Rosendal graphs and applying them to Polish groups.
result Groups with Cayley--Abels--Rosendal graphs are topological analogues of finitely generated groups.
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.
The Monge-Cayley-Salmon theorem is extended for ruled submanifolds.
problem Generalization of a classical theorem for ruled submanifolds.
method Elementary geometric measure theory.
result Generalization of the Monge-Cayley-Salmon theorem proved.
Cayley cones in the octonions O that are ruled by oriented 2-planes are equivalent to pseudoholomorphic curves in the Grassmannian of oriented 2-planes G(2,8). The well known twistor fibration G(2,8)−>S6 is used to prove the existence of immersed higher-genus pseudoholomorphic curves in $\gro$. Equivale…
Using octonions and the triality property of Spin(8), we find explicit formulae for the Lie brackets of the exceptional simple real Lie algebras f4 and f4∗, i.e. the Lie algebras of the isometry groups of the Cayley projective plane and the Cayley hyperbolic plane. As an application, we cla…
AI can identify simple groups and match algebraic tables, even with limited training.
problem Can AI learn algebraic structures?
method Machine learning techniques (SVM, neural classifiers) applied to finite groups and rings.
result AI can correctly identify simple groups and match algebraic tables for small structures.
Functions of several octonion variables are investigated and integral representation theorems for them are proved. With the help of them solutions of the ∂~-equations are studied. More generally functions of several Cayley-Dickson variables are considered. Integral formulas of the Martinelli-Bochner,…
The paper studies properties of Artin monoid Cayley graphs and their quasi-isometry to Deligne complexes.
problem Investigate properties of Artin monoid Cayley graphs.
method Show quasi-isometry to modified Deligne complex, address infinite diameter conjecture.
result Prove conjecture about infinite diameter for Artin groups containing specific subgroups.
Local SU(3)-structures on an oriented submanifold of Spin(7)-manifold are determined and their types are characterized in terms of the shape operator and the type of the Spin(7)-structure. An application to Bryant \cite{MR89b:53084} and Calabi \cite{MR24 #A558} examples is given. It is shown that the product of a Cayle…
We exhibit a family of homogeneous hypersurfaces in affine space, one in each dimension, generalising the Cayley surface.
On realizations of the complex Lie groups (E6,R)C,(E6,C)C,(E6,H)C and those real formsmath.RA The paper explores different realizations of complex Lie groups using various number fields.
problem Defining and understanding Lie groups with different number fields.
method Using Cayley algebras and fields of real numbers, complex numbers, split complex numbers, quaternions, and split quaternions to define and study Lie groups.
result The structure of Lie groups (E6,R)C,(E6,C)C,(E6,H)C and their real forms are determined. This paper explores 4-planes in Spin(7) manifolds with symplectic structures.
problem Characterizing 4-planes in Spin(7) manifolds with symplectic structures.
method Detailed analysis of differential forms, including the Cayley 4-form, and exploration of mirror duality.
result Enhanced understanding of the interplay between Spin(7)-structures and symplectic geometry.
Following an idea of Dadok, Harvey and Lawson, we apply the triality property of SO(8) to study the comass of certain self-dual 4-forms on R^8. In particular, we prove that the Cayley 4-form has comass 1 and that any self-dual 4-form realizing the maximal Wirtinger ratio is SO(8)-conjugate to the Cayley 4-form. We also…
We prove an existence theorem for Spin(7)-instantons, which are highly concentrated near a Cayley submanifold; thus giving a partial converse to Tian's foundational compactness theorem. As an application, we show how to construct Spin(7)-instantons on Spin(7)-manifolds with suitable local K3 Cayley fibrations. This rec…
The covering spectrum is a geometric invariant of a Riemannian manifold, more generally of a metric space, that measures the size of its one-dimensional holes by isolating a portion of the length spectrum. In a previous paper we demonstrated that the covering spectrum is not a spectral invariant of a manifold in dimens…
The Cayley hyperbolic space minimizes volume entropy among finite-volume metrics.
problem Volume entropy rigidity in Cayley hyperbolic spaces.
method Repairing a gap in the proof of volume entropy rigidity theorem.
result Cayley hyperbolic space minimizes volume entropy.
Natural volume forms defined for pseudo-Finslerian manifolds with specific metrics.
problem Defining natural volume forms on pseudo-Finslerian manifolds with m-th root metrics. method Definitions depend on the parity of m, expressed in terms of Cayley hyperdeterminants. result Volume forms computation simplified by avoiding integration over the indicatrix.
This paper develops graph theory for racks and quasigroups.
problem Characterizing and realizing right quasigroups and related structures.
method Study of graph markings, Schreier graphs, and Cayley graphs.
result All right quasigroups are realizable by specific types of graphs.