In order to generalize finite element methods to differential forms, Arnold, Falk, and Winther constructed two families of spaces of polynomial differential forms on a simplex T, the PrΛk(T) spaces and the Pr−Λk(T) spaces, where k is the degree of the form and r is the degree of its coe…
Symplectic coordinates found on projective structures on orbifolds.
problem Symplectic structure on deformation spaces of convex projective structures.
method Global Darboux coordinates system construction and symplectic space decomposition.
result Symplectic form on deformation space of convex projective structures.
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.
Finite element exterior calculus refers to the development of finite element methods for differential forms, generalizing several earlier finite element spaces of scalar fields and vector fields to arbitrary dimension n, arbitrary polynomial degree r, and arbitrary differential form degree k. The study of finite …
In this article, we construct a new para-Kähler structure (G,J,Ω) in the space of oriented geodesics L(M) in a non-flat, real space form M. We first show that the para-Kähler metric G is scalar flat and when M is a 3-dimensional real space form, G is loc…
The paper defines and analyzes f-biharmonic θα-slant curves in S-space forms.
problem Characterizing f-biharmonic θα-slant curves in S-space forms. method Provided a concise overview, derived a key equation, and analyzed it to establish conditions for θα-slant curves to be f-biharmonic. result Established necessary and sufficient conditions for θα-slant curves to be f-biharmonic. Formula decomposes multiplicative forms on Poisson groupoids into two parts.
problem Decomposing multiplicative forms on Poisson groupoids.
method Provided a formula to decompose multiplicative k-forms into a 1-cocycle and a ρ-compatible form.
result Multiplicative forms on Poisson groupoids form a differential graded Lie algebra (DGLA) crossed module.
Decomposes harmonic forms on almost Kähler manifolds, revealing non-trivial structure.
problem Primitive decomposition of harmonic forms on compact almost Kähler manifolds.
method Primitive decomposition of ∂ˉ,∂, Bott-Chern and Aeppli-harmonic (k,k)-forms. result Primitive components of harmonic forms are constants multiples of ωk. H−holomorphic curves are solutions of a specific modification of the pseudoholomorphic curve equation in symplectizations involving a harmonic 1−form as perturbation term. In this paper we compactify the moduli space of H−holomorphic curves with a priori bounds on the harmonic 1−forms.
It is proved that the isometry classes of pointed connected complete Riemannian n-manifolds form a Polish space, M∗∞(n), with the topology described by the C∞ convergence of manifolds. This space has a canonical partition into sets defined by varying the distinguished point into each manifo…
We find the characterization of maximum dimensional proper-biharmonic integral C-parallel submanifolds of a Sasakian space form and then classify such submanifolds in a 7-dimensional Sasakian space form. Working in the sphere S7 we explicitly find all 3-dimensional proper-biharmonic integral C…
This paper explains a 2-form on moduli spaces using quasi-Hamiltonian and Dirac geometry.
problem Finite-dimensional construction of a 2-form on moduli spaces.
method Quasi-Hamiltonian techniques and Dirac geometry.
result Finite-dimensional construction of a distinguished 2-form on moduli spaces.
Given a family f:X→S of canonically polarized manifolds, the unique Kähler-Einstein metrics on the fibers induce a hermitian metric on the relative canonical bundle KX/S. We use a global elliptic equation to show that this metric is strictly positive on X, unless the fam…
The paper proves isomorphisms between two complexes related to singular foliations.
problem Understanding the isomorphisms between two complexes associated with singular foliations.
method Analyzing the quotient map and proving isomorphisms in specific cases.
result Isomorphisms between the complexes of differential forms on the leaf space and basic differential forms on the manifold.
Let (M,F) be a foliated manifold. We prove that there is a canonical isomorphism between the complex of base-like forms Ωb∗(M,F) of the foliation and the "De Rham complex" of the space of leaves M/F when considered as a "diffeological" quotient. Consequently, the two corresponding …
Outer billiards defined on geodesics surfaces in 3D space forms.
problem Defining and analyzing outer billiards on geodesics in 3D space forms.
method Defined an outer billiard map on the space of oriented geodesics, showing diffeomorphism and symplectomorphism properties.
result Outer billiard map is a diffeomorphism and symplectomorphism under certain conditions.
The paper studies webs formed by rational curves on moduli spaces and their abelian relations.
problem Analyzing the structure and abelian relations of webs formed by rational curves on moduli spaces.
method Recalling classical results, focusing on the 6-web, using abelian 2-forms, and applying Damiano's approach.
result The (n+3)-web W0,n+3 has maximal rank with rational abelian relations for any n≥2. Suppose that we have a compact Kähler manifold X with a very ample line bundle L. We prove that any positive definite hermitian form on the space H0(X,L) of holomorphic sections can be written as an L2-inner product with respect to an appropriate hermitian metric on L. We appl…
Given d∈N, g∈N∪{0}, and an integral vector κ=(k1,…,kn) such that ki>−d and k1+⋯+kn=d(2g−2), let ΩdMg,n(κ) denote the moduli space of meromorphic d-differentials on Riemann surfaces of genus g whose zeros and poles have orders prescribed by κ. We…
Study homotopy equivalence of spaces of gradient-like flows and Morse functions on surfaces.
problem Understanding the topology of spaces of smooth functions and flows on surfaces.
method Proves homotopy equivalence of spaces of gradient-like flows and Morse functions on surfaces, with detailed decomposition into orbits.
result Spaces of gradient-like flows and Morse functions on surfaces are homotopy equivalent to manifolds.
Extends Ooguri-Vafa symplectic form to framed Higgs bundles.
problem Local model for Hitchin moduli spaces near discriminant locus.
method Identifies Ooguri-Vafa form with Atiyah-Bott form on framed connections.
result Identifies Ooguri-Vafa metric with Hitchin's L2-metric on Hitchin section. The paper defines and proves the existence of curves in Riemannian manifolds with prescribed angles to torse-forming vector fields.
problem Existence of curves with prescribed angles to torse-forming vector fields in Riemannian manifolds.
method Introducing the notion of a prescribed angle curve and proving its existence for torse-forming vector fields.
result Existence of prescribed angle curves in Riemannian manifolds associated with torse-forming vector fields.
We give a graphical theory of integral indefinite binary Hamiltonian forms f analogous to the one by Conway for binary quadratic forms and the one of Bestvina-Savin for binary Hermitian forms. Given a maximal order O in a definite quaternion algebra over Q, we define the waterworld of f, analog…
The odd signature operator is a Dirac operator which acts on the space of differential forms of all degrees and whose square is the usual Laplacian. We extend the result of [15] to prove the gluing formula of the zeta-determinants of Laplacians acting on differential forms of all degrees with respect to the boundary co…
The space H of "almost calibrated" (1,1) forms on a compact Kähler manifold plays an important role in the study of the deformed Hermitian-Yang-Mills equation of mirror symmetry as emphasized by recent work of the second author and Yau, and is related by mirror symmetry to the space of positive Lagrangian…
The paper studies Clifford-Bianchi groups acting on hyperbolic spaces and their properties.
problem Understanding the actions of Clifford-Bianchi groups on hyperbolic spaces.
method Developed the abstract and computational theory for determining fundamental domains and generators for orders in low dimensions.
result Found that Clifford-Bianchi groups are arithmetic subgroups of SO(1, n+1) and their Möbius action.
The study defines and constructs hypersurfaces in a product of two space forms.
problem Characterizing hypersurfaces in a product of two space forms.
method Explicit construction using parallel families of hypersurfaces and isoparametric hypersurfaces.
result Classification of hypersurfaces with constant mean curvature and constant product angle function.
On a closed connected oriented manifold M we study the space M∥(M) of all Riemannian metrics which admit a non-zero parallel spinor on the universal covering. Such metrics are Ricci-flat, and all known Ricci-flat metrics are of this form. We show the following: The space M∥(M) is a smooth …
The paper defines a complete geodesic metric for high energy spaces in Kähler manifolds.
problem Defining a metric for high energy spaces in Kähler manifolds.
method Endowing the high energy space with a metric that makes it a complete geodesic metric space.
result The geodesic metric space (Ep(X,θ),dp) is uniformly convex for p>1. The paper proves a pseudo-Kähler structure on a torus's projective space.
problem Existence of a pseudo-Kähler structure on a torus's projective space.
method Proved the existence of a pseudo-Kähler structure using complex, symplectic, and Riemannian compatibility.
result Existence of a moment map for the SL(2, R) action over the deformation space.
The paper explores Hodge decomposition and Hard Lefschetz Condition on almost Kähler manifolds.
problem Analyzing harmonic forms and Hodge decomposition on almost Kähler manifolds.
method Using Hodge decomposition and the Hard Lefschetz Condition to study almost Kähler manifolds.
result The spaces of harmonic forms have the Hodge decomposition and the Hard Lefschetz Condition is satisfied.
New theorem generalizes contact manifolds with symplectic properties.
problem Generalizing contact manifolds with symplectic structures.
method Introducing regular contact manifolds and proving properties of fibrations.
result Existence of unique symplectic form and prequantization.
We define local Hardy spaces of differential forms hDp(∧T∗M) for all p∈[1,∞] that are adapted to a class of first order differential operators D on a complete Riemannian manifold M with at most exponential volume growth. In particular, if D is the Hodge--Dirac operator on $…
We consider a compact Riemann surface R of arbitrary genus, with a finite number of non-overlapping quasicircles, which separate R into two subsets: a connected Riemann surface Σ, and the union O of a finite collection of simply-connected regions. We prove that the Schiffer integral operator mapping t…
We introduce and analyze a form of variance-reduced Q-learning. For γ-discounted MDPs with finite state space X and action space U, we prove that it yields an ε-accurate estimate of the optimal Q-function in the ℓ∞-norm using $\mathcal{O} \left(\left(\frac{D}{ ε^2 (1-γ)^3} \ri…
Let M be a complete Sasakian sub-Riemannian 3-manifold of constant Webster scalar curvature κ. For any point p∈M and any number λ∈R with λ2+κ>0, we show existence of a C2 spherical surface Sλ(p) immersed in M with constant mean curvature λ. Our construction recovers in par…
Holomorphic symplectic structure on Lagrangian moduli space.
problem Understanding the structure of Lagrangian submanifolds in hyperKähler manifolds.
method Proving the existence of a natural holomorphic symplectic structure on the relative Albanese over the moduli space.
result The relative Albanese over the moduli space of complex Lagrangian submanifolds has a natural holomorphic symplectic structure.
Extended metric defined on Siegel-Jacobi space using invariant forms.
problem Defining a metric on the extended Siegel-Jacobi upper half space.
method Matrix embedding, pre-Iwasawa decomposition, invariant forms, sum of squares of forms.
result Invariant metric on the extended Siegel-Jacobi upper half space is derived.
Calculates volumes of linear subvarieties in moduli spaces of Abelian differentials.
problem Computing volumes of linear subvarieties in moduli spaces of Abelian differentials.
method Analyzes the projective bundle and its extensions, uses Hodge norm curvature and intersection theory.
result Volumes of linear subvarieties can be computed using self-intersection numbers of tautological line bundles.
In [5], D. Fetcu and C. Oniciuc presented the classification result for biharmonic C-parallel Legendrian submanifolds in 7-dimensional Sasakian space forms. However, it is incomplete. In this paper, all such submanifolds are explicitly determined.
Study classifies hypersurfaces in 4D Lorentz-Minkowski space using specific operators.
problem Classifying tubular hypersurfaces in 4D Lorentz-Minkowski space.
method Analysis of Gauss map and linearized operators L1 and L2. result Classifications of hypersurfaces with specific types of Gauss maps.
We find the homogenous Kähler isomorphism FC which expresses the Kähler two-form on the Siegel-Jacobi domain D1J=C×D1 as the sum of the Kähler two-form on C and the one on the Siegel ball D1. The classical motion and quantum evolution on D1J…
Defines a metric and form for a bundle moduli space, leading to a zero-curvature formulation.
problem Formulating a metric and form for a bundle moduli space.
method Defines an algebraic metric and closed 3-form on a subspace of the moduli of G-bundles. result Shows a zero-curvature formulation for a σ-model with target the moduli space. Topological proof of Weil-Petersson symplectic form using Fenchel-Nielsen coordinates.
problem Proving Wolpert's formula for the Weil-Petersson symplectic form.
method Introducing a cell decomposition and groupoid cocycle on a surface to represent points in Teichmüller space.
result Topological proof of Wolpert's formula for the Weil-Petersson symplectic form.
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.
In the preceding note math.DG/0610917 the Λk−1C--spectral sequence, whose first term is composed of \emph{secondary iterated differential forms}, was constructed for a generic diffiety. In this note the zero and first terms of this spectral sequence are explicitly computed for infinite jet spaces. In par…
Geometrically classifies total stability spaces for Dynkin diagrams.
problem Classifying total stability spaces for triangulated categories.
method Constructing a geometric model of root categories as hQ-gons and proving isomorphisms. result Total stability spaces ToStDb(Q)/[2] are isomorphic to moduli spaces of stable hQ-gons. This paper is devoted to an elementary new construction of 1-singular Gelfand-Tsetlin modules using complex geometry. We introduce a universal ring Do together with the vector space S=S(Do) with basis Bo=B(Do) formed from some local distributi…