Let M=(M,OM) be a smooth supermanifold with connection ∇ and Batchelor model OM≅ΓΛE∗. From (M,∇) we construct a connection on the total space of the vector bundle E→M. This reduction of ∇ is well-defined independently of …
Quillen connection links Riemann surfaces to projective structures.
problem Understanding the relationship between Riemann surfaces and projective structures.
method Using the Quillen connection and Weil-Petersson form on moduli stacks.
result Holomorphic isomorphism between bundles of connections and uniformization.
New C-connection characterizes 4D spaces conformal to Einstein spaces.
problem Characterizing 4D spaces conformal to Einstein spaces.
method Introducing C-connection, a Weyl connection that preserves conformal invariance. result Characterizes non-degenerate spaces conformal to Einstein spaces.
If M=(M,∇) is an affine surface, let Q(M):=ker(H+m−11ρs) be the space of solutions to the quasi-Einstein equation for the crucial eigenvalue. Let M~=(M,∇~) be another affine structure on M which is strongly projectively flat. We sh…
In the last section of \cite{CompHyp} it is proved that the map I is a finite-sheeted covering map between P and M. As M is simply connected it is deduced that I is a homeomorphism. The fact that P is connected is missing. Here we provide a proof.
Study on harmonic Higgs bundles with vanishing endormorphism and eigenvalues of Q.
problem Analyzing integrable harmonic Higgs bundles with specific conditions.
method tt*-geometry, vanishing endormorphism, holomorphic connections, eigenvalues of Q.
result Vanishing endormorphism implies vanishing Higgs field and invariant metrics.
Torsors over moduli spaces of vector bundles with fixed determinant.
problem Understanding connections on vector bundles over curves.
method Algebraic geometry and sheaf theory.
result Moduli space of vector bundles has a natural torsor structure.
A 3D space of hyperbolic manifolds is connected but not path-connected.
problem Proving connectivity and non-path-connectedness of framed hyperbolic 3-manifolds.
method Two proofs using density theorems for Kleinian groups, constructing dense sets of framings, and discussing paths.
result The space of framed infinite volume hyperbolic 3-manifolds is not path-connected.
The paper classifies Lie algebroids and their connections, modulating principal objects.
problem Classifying and studying Lie algebroids and their connections.
method Classifying integrable transitive Lie algebroids, introducing Higgs bundles, and using Tannakian categories.
result Moduli spaces of principal \(G\)-bundles and Higgs bundles are semiprojective varieties.
The paper studies connectivity properties of Morse complexes as simplicial complexes grow.
problem Understanding connectivity of Morse complexes as simplicial complexes evolve.
method Bestvina-Brady Morse theory applied to a generalized Morse complex.
result Proves M(Δ) becomes arbitrarily highly connected as Δ grows. Establishes a connection between skein modules and algebraic sets.
problem Understanding the structure of stated SLn-skein modules. method Uses algebraic homomorphisms and isomorphisms to relate skein modules to algebraic structures.
result Proves the isomorphism between stated skein modules and universal representation algebras.
The article studies conic connections on complex manifolds and their geometric properties.
problem Characterizing and understanding conic connections on complex manifolds.
method Develops a new approach to the cubic torsion and studies the geometric conditions for its vanishing.
result Provides a geometric condition characterizing the vanishing of cubic torsion.
The paper constructs a canonical connection on bundles over Riemann surfaces and relates it to the theta divisor.
problem Investigating connections on Riemann surface bundles and their geometric properties.
method Holomorphic connections and symplectic geometry on moduli spaces.
result A symplectic structure-preserving isomorphism between moduli spaces of connections and holomorphic connections on theta divisors.
Suppose a finitely generated group G is hyperbolic relative to P a set of proper finitely generated subgroups of G. Established results in the literature imply that a "visual" metric on ∂(G,P) is "linearly connected" if and only if the boundary ∂(G,P) has no cut poin…
Develops connections and Chern-Weil theory for Lie groupoids.
problem Defining and studying connections on Lie groupoids.
method Integrable distribution, Atiyah sequence, characteristic classes.
result Chern-Weil theory for Lie groupoids.
The paper shows how to uniquely determine a connection up to gauge.
problem Determining a connection up to gauge from its holonomies.
method Using hyperbolic dynamical systems and transport operators.
result The primitive trace map is locally injective near generic points.
In this paper, we study distributed stochastic optimization to minimize a sum of smooth and strongly-convex local cost functions over a network of agents, communicating over a strongly-connected graph. Assuming that each agent has access to a stochastic first-order oracle (SFO), we propose a novel distribut…
Analyzes Berry phases and connection matrices on Siegel-Jacobi spaces.
problem Understanding Berry phases and connection matrices on Siegel-Jacobi spaces.
method Examines the Siegel-Jacobi disk and upper half-plane, calculates connection matrices and covariant derivatives.
result Calculates the connection matrix and covariant derivatives on the extended Siegel-Jacobi upper half-plane.
Consider the moduli space Mg of Riemann surfaces of genus g≥2 and its Deligne-Munford compactification Mgˉ. We are interested in the branch locus Bg for g>2, i.e., the subset of Mg consisting of surfaces with automorphisms. It is well-known that…
Constructs a new mathematical structure for Riemann surfaces with projective structures.
problem No specific problem stated; abstract focuses on construction of a new mathematical structure.
method Constructs a T^*B_g(r)-torsor H_g(r) over B_g(r) using stable vector bundles and holomorphic connections.
result Shows that H_g(r) has a holomorphic symplectic structure compatible with the T^*B_g(r)-torsor structure.
Let (M,π,D) be a Poisson manifold endowed with a flat, torsion-free contravariant connection. We show that if D is an F-connection then there exists a tensor T such that DT is the metacurvature tensor introduced by E. Hawkins in his work on noncommutat…
Let π:P→M be a principal bundle and p an invariant polynomial of degree r on the Lie algebra of the structure group. The theory of Chern-Simons differential characters is exploited to define an homology map χk:H2r−k−1(M)×Hk(F/G)→R/Z, for k<r−1, …
Study on averaging geometric structures in Finsler spaces with Lorentzian signature.
problem Averaging geometric structures in Finsler spaces with Lorentzian signature.
method Definition of an average connection without using the timelike vector field.
result No direct relation between the two averaged objects.
An almost Clifford and an almost Cliffordian manifold is a G--structure based on the definition of Clifford algebras. An almost Clifford manifold based on $\mathcal O:= \cc l (s,t)$ is given by a reduction of the structure group GL(km,R) to GL(m,O), where k=2s+t and m∈N. An…
Classifies two families of simply connected 7-manifolds with minimal homological complexity.
problem Classifying simply connected rational homology 7-spheres that are not 2-connected.
method Complete classification of two families of manifolds using Milnor's λ-invariant and Eells-Kuiper μ-invariant.
result Minimal homological complexity among simply connected rational homology 7-spheres that are not 2-connected.
Symmetries of Einstein-Weyl manifolds can be extended from boundary surfaces.
problem Extending symmetries from boundary surfaces to Einstein-Weyl manifolds.
method Starting from a symmetry of conformal Cartan connection on a boundary surface, proving symmetries can be extended.
result Symmetries of conformal Cartan connection on the boundary can be extended to symmetries of the Einstein-Weyl manifold.
We investigate the geometry of the Kodaira moduli space M of sections of π:Z→P1, the normal bundle of which is allowed to jump from O(1)n to O(1)n−2m⊕O(2)m⊕Om. In particular, we identify the natural assumptions which guarantee tha…
The dynamics of holomorphic 1-forms are studied, showing ergodic foliations and connected spaces.
problem Analyzing the dynamics of absolute period foliations in strata of holomorphic 1-forms.
method Using cohomology classes and isoperiodic forms, the authors show ergodicity and connectedness of spaces.
result The absolute period foliation is ergodic on the area-1 locus and has non-dense leaves in explicit suborbifolds.
Constructs a unique Levi-Civita connection for generalised metrics.
problem Non-uniqueness of generalised Levi-Civita connections.
method Geometrically constructs a canonical generalised Levi-Civita connection.
result Decomposes the generalised Riemann curvature tensor in terms of classical geometric data.
Let FM,MM be the bundles of linear frames and Riemannian metrics of a manifold M, respectively. The existence of a unique DiffM-invariant connection form on J1MM×MFM→J1MM, which is Riemannian with respect to the universal metric on $J^1\mathcal{M}_M\times_MTM…
Characterizes Lorentzian manifolds with semi-symmetric metric connections.
problem Characterizing Lorentzian manifolds with specific metric connections.
method Analyzing semi-symmetric metric connections with vanishing curvature and recurrent torsion.
result Establishes conditions for perfect fluid and generalized Robertson-Walker spacetimes.
Study mSpin(7)-dDT connections on manifolds with mSpin(7)-structures.
problem Understanding moduli spaces of mSpin(7)-dDT connections. method Introduced and studied mSpin(7)-dDT connections using fully nonlinear PDEs. result Moduli space MmSpin(7)′ has finite expected dimension and smoothness under certain conditions. Let N be a compact, connected, nonorientable surface of genus g with n boundary components. Let λ be a simplicial map of the complex of curves, C(N), on N which satisfies the following: [a] and [b] are connected by an edge in C(N) if and only if λ([a]) and λ([b]) are connected …
The study characterizes Nash maps between semialgebraic sets and their properties.
problem Existence of surjective Nash maps between semialgebraic sets.
method Characterization of semialgebraic subsets and their images under Nash maps.
result Characterization of semialgebraic sets that are Nash images of the unit ball.
We consider a regular distribution D in a Riemannian manifold (M,g). The Levi-Civita connection on (M,g) together with the orthogonal projection allow to endow the space of sections of D with a natural covariant derivative, the intrinsic connection. Hence we have two different covariant deri…
In this paper we will show the following result: Let N be a complete (noncompact) connected orientable Riemannian three-manifold with nonnegative scalar curvature S≥0 and bounded sectional curvature Ks≤K. Suposse that Σ⊂N is a complete orientable connected area-minimi…
Study invariant connections on multivariate Gaussian distributions.
problem Understanding statistical connections on multivariate Gaussian distributions.
method Investigate invariant connections on N0n with the Fisher metric. result Explicitly determined invariant connections and their moduli spaces.
Topological twists for 4d N=2 theories depend on spacetime type, gerbe connections, and generalized spin-c structures.
problem Defining topologically twisted partition functions for 4d N=2 theories.
method Topological twisting for general 4d N=2 theories, introducing generalized spin-c structures.
result Topological partition functions depend on spacetime type, gerbe connections, and generalized spin-c structures.
The main goal of this article is to construct some geometric invariants for the topology of the set F of flat connections on a principal G-bundle P⟶M. Although the characteristic classes of principal bundles are trivial when F=∅, their classical Chern-Weil cons…
The aim of this paper is to study from the point of view of linear connections the data (M,D,g,W), with M a smooth (n+p) dimensional real manifold, (D,g) a \textit{n}\textit{\emph{dimensional semi-Riemannian distribution}}\emph{}on M, G the conformal structure generated by $g…
New connections found on zero-mean multivariate normal distributions.
problem Characterizing statistical connections on zero-mean multivariate normal distributions.
method Investigating invariant conjugate symmetric statistical connections on the submanifold of zero-mean multivariate normal distributions.
result Invariant connections on zero-mean multivariate normal distributions are not uniquely characterized by invariance under the general linear group action.
This paper studies generic properties of connections on vector bundles, solving cohomological equations and proving opaque connections.
problem Generic properties of unitary connections on vector bundles over Riemannian manifolds.
method Introduction of operators of uniform divergence type and perturbative arguments from spectral theory.
result The existence of twisted Conformal Killing Tensors (CKTs) is generically solved, and connections are generically opaque.
Connected boundaries of strata of differentials are always connected in various compactifications.
problem Understanding the connectedness of boundaries of differentials' strata in various compactifications.
method Explicit degeneration techniques, algebraic compactifications, and properties of Teichmüller curves.
result The boundaries of differentials' strata are always connected in any complete algebraic compactification.
Newton's method tackles nonlinear mappings into vector bundles with connections and retractions.
problem Finding zeros of mappings from a manifold into a vector bundle.
method Local convergence using differentiability concepts, Banach space Riemannian distance, and affine covariant damping strategy.
result Illustrated application to generalized non-symmetric eigenvalue problems.
Denote by A(κ) the set of all compact Alexandrov surfaces with curvature bounded below by κ without boundary, endowed with the topology induced by the Gromov-Hausdorff metric. We determine the connected components of A(κ) and of its closure.
Let (X,x0) be any one--pointed compact connected Riemann surface of genus g, with g≥3. Fix two mutually coprime integers r>1 and d. Let MX denote the moduli space parametrizing all logarithmic SL(r,C)--connections, singular over x0, on vector bundles over X of degree…
We develop various properties of symmetric generalized complex structures (in connection with their holomorphic space and B-field transformations), which are analogous to the well-known results of Gualtieri on skew-symmetric generalized complex structures. Given a symmetric or skew-symmetric generalized complex structu…
In the previous work ([14]) we introduced the well-posed boundary conditions P−,L0 and P+,L1 for the odd signature operator to define the refined analytic torsion on a compact manifold with boundary. In this paper we discuss the gluing formula of the refined…