Constructs geometries with nonvanishing curvature and essential automorphisms.
problem Creating geometries with nonvanishing curvature and essential automorphisms.
method Using elements of the kernel of the Kostant Laplacian to construct homogeneous Cartan geometries, then modifying them to make base manifolds compact.
result Infinite families of regular normal Cartan geometries with nonvanishing curvature and essential automorphisms on closed manifolds for higher rank parabolic model geometries.
Study surfaces with nonvanishing Gauss curvature in Lorentz-Minkowski space.
problem Characterizing surfaces with specific curvature properties in Lorentz-Minkowski space.
method Analyzing surfaces satisfying ΔIIIx = Ax, where III is the second fundamental form.
result Surfaces are either minimal or pseudospheres with real or imaginary radii.
Study properties of surfaces with nonvanishing third fundamental form.
problem Investigate surfaces with finite III-type properties.
method Analyze Laplace operators and third fundamental form of surfaces in E3.
result Present surfaces of revolution with constant R and nonvanishing Gauss curvature.
In the study manifolds of Ricci curvature bounded below, a stumbling obstruction is the lack of links between large-scale geometry and small-scale geometry at a fixed reference point. There have been few links (volume, dimension) when the unit ball at the point is not collapsed, that is, vol(B1(p))≥v>0. …
Two types of nonvanishing results are presented for compact Kähler varieties.
problem Deriving geometric consequences from numerical information in Kähler geometry.
method Analyzing non-uniruled varieties and hyperkähler manifolds to establish nonvanishing results for adjoint and nef bundles.
result Strong abundance-type results are obtained in dimension 4.
The following result is proved: Consider a 4-dimensional Kaehler manifold M with nonvanishing Bochner tensor B. Then any holomorphic transformation of M, which preserves B is a homothety.
We present some formulae related to the Chern-Ricci curvatures and scalar curvatures of special Hermitian metrics. We prove that a compact locally conformal Kähler manifold with constant nonpositive holomorphic sectional curvature is Kähler. We also give examples of complete non-Kähler metrics with pointwise negative c…
Curves can bound only finitely many developable surfaces.
problem Bounding developable surfaces with nonvanishing mean curvature.
method Proof of finiteness for developable surfaces with prescribed boundary curves.
result Generic curves bound only finitely many developable surfaces.
Curves with constant curvature are flexible and can be deformed.
problem Understanding the flexibility of curves with constant curvature.
method Proving the parametric C1-dense relative h-principle for curves of constant curvature. result Two knots of constant curvature are isotopic and homotopic if their self-linking numbers are equal.
Smooth curves with specific curvature can be closely approximated.
problem Approximating smooth curves with prescribed curvature.
method Application of h-principle to C1-dense approximation of curves. result Existence of C∞ knots with prescribed curvature. We compute the value of the simplicial volume for closed, oriented Riemannian manifolds covered by H2×H2 explicitly, thus in particular for products of closed hyperbolic surfaces. This gives the first exact value of a nonvanishing simplicial volume for a manifold of nonconstant curvature.
Classifies 3-manifolds with Killing vector fields, extending results from Riemannian to Lorentzian.
problem Classifying Riemannian and Lorentzian 3-manifolds with Killing vector fields.
method Analyzing scalar curvature and Ricci tensor, using quotient metrics and conformal flatness conditions.
result Complete local classification of Riemannian 3-manifolds and extension to Lorentzian.
The paper proves rigidity for warped product spaces with degenerate ends.
problem Proving rigidity for warped product spaces with degenerate ends.
method Analyzing scalar curvature for specific classes of warped product spaces.
result Proves scalar curvature extremality and rigidity for certain degenerate spaces.
In this paper, we generalize the Cao-Yau's gradient estimate for the sum of squares of vector fields up to higher step under assumption of the generalized curvature-dimension inequality. With its applications, by deriving a curvature-dimension inequality, we are able to obtain the Li-Yau gradient estimate for the CR he…
We study a multiply warped products manifold associated with the Reissner-Nordstrom metric to investigate the physical properties inside the black hole event horizons. It is shown that, different from the uncharged Schwarzschild metric, the Ricci curvature components inside the Reissner-Nordstrom black hole horizons ar…
We investigate the Pin−(2)-monopole invariants of symplectic 4-manifolds and Kähler surfaces with real structures. We prove the nonvanishing theorem for real symplectic 4-manifolds which is an analogue of Taubes' nonvanishing theorem of the Seiberg-Witten invariants for symplectic 4-manifolds. Further…
A new topological gap theorem improves the systole of 3-manifolds with positive scalar curvature.
problem Improving the systole of 3-manifolds with positive scalar curvature.
method Weak inverse mean curvature flow.
result The systole of 3-manifolds is no greater than an improved constant c ≈ 5.44π.
Graph manifolds' Thurston norms are sums of linear functionals, and every such norm can be realized.
problem Understanding Thurston norms of graph manifolds and their realizability.
method Analyzing the structure of Thurston norms as sums of linear functionals and showing realizability.
result Every Thurston norm of a graph manifold can be expressed as a sum of absolute values of linear functionals with rational coefficients.
The paper proves nonvanishing cohomology for ball quotient fundamental groups.
problem Proving nonvanishing cohomology for ball quotient fundamental groups.
method Using arithmetic lattices and profinite completions, the paper constructs an open subgroup with nontrivial cohomology.
result The virtual cohomological dimension of the fundamental group is at least 2n. In this article it is shown that the study of harmonic diffeomorphisms, with nonvanishing Hopf differential, reduces to the study of the Beltrami equation of a certain type: the imaginary part of the logarithm of the Beltrami function coincides with the imaginary part of the logarithm of the Hopf differential, therefor…
In this paper we discuss curvature tensors in the context of Absolute Parallelism geometry. Different curvature tensors are expressed in a compact form in terms of the torsion tensor of the canonical connection. Using the Bianchi identities some other identities are derived from the expressions obtained. These identiti…
We give an example of a 3-component smoothly slice boundary link, each of whose components has a genus one Seifert surface, such that any metaboliser of the boundary link Seifert form is represented by 3 curves on the Seifert surfaces that form a link with nonvanishing Milnor triple linking number. We also give a gener…
Study cohomology of curve moduli spaces, finding new nonvanishing groups.
problem Computing cohomology of moduli spaces of curves.
method Graph complexes related to embedding spaces.
result New infinite families of nonvanishing unstable cohomology groups on Mg. We determine several necessary and sufficient conditions for a closed almost-complex orbifold Q with cyclic local groups to admit a nonvanishing vector field. These conditions are stated separately in terms of the orbifold Euler-Satake characteristics of Q and its sectors, the Euler characteristics of the underlyin…
We provide the first example of a Legendrian knot with nonvanishing contact homology whose Thurston-Bennequin invariant is not maximal.
The paper finds a geometric lower bound for the first positive eigenvalue of the rough Laplacian on 1-forms.
problem Estimating the first positive eigenvalue of the rough Laplacian on 1-forms.
method Establishes a geometric lower bound using assumptions on Ricci curvature, diameter, and Riemann curvature tensor.
result The first positive eigenvalue of the rough Laplacian on 1-forms is bounded below by a positive constant.
In this paper, we prove the infinite dimensionality of some local and global cohomology groups on abstract Cauchy-Riemann manifolds.
Suppose that the inverse image of the zero vector by a continuous map f:Rn→Rq has an isolated point P. There is a local obstruction to removing this isolated zero by a small perturbation, generalizing the notion of index for vector fields, the q=n case. The existence of a continuous map $g…
We obtain asymptotics of sequences of the holomorphic sections of the pluricanonical bundles on ball quotients associated to closed geodesics. A nonvanishing result follows.
Sharp pinching theorem for submanifolds in spheres.
problem Characterizing submanifolds in spheres based on curvature bounds.
method Conformal method of Fischer-Colbrie, Shen & Ye and Catino, Mastrolia & Roncoroni.
result Complete submanifolds with specific curvature bounds are either totally geodesic or Clifford tori/Veronese surfaces.
The Navier-Stokes equations on certain manifolds can perform universal computation.
problem Computational universality in viscous fluids.
method Cosymplectic geometry and harmonic 1-forms.
result Stationary Navier-Stokes solutions exhibit Turing completeness.
We introduce a complete obstruction to the existence of nonvanishing vector fields on a closed orbifold Q. Motivated by the inertia orbifold, the space of multi-sectors, and the generalized orbifold Euler characteristics, we construct for each finitely generated group Γ an orbifold called the space of Γ-sectors o…
We investigate the filling area conjecture, optimal systolic inequalities, and the related problem of the nonvanishing of certain linking numbers in 3-manifolds.
Manifolds endowed with torsion and nonmetricity are interesting both from the physical and the mathematical points of view. In this paper, we generalize some results presented in the literature. We study Einstein manifolds (i.e., manifolds whose symmetrized Ricci tensor is proportional to the metric) in d dimensions wi…
Using toric geometry we give an explicit construction of the compact steady solitons for pluriclosed flow first constructed in arXiv:1802.00170. This construction also reveals that these solitons are generalized Kähler in two distinct ways, with vanishing and nonvanishing Poisson structure. This gives the first example…
We define an invariant of based transverse links, as a well-defined element inside the equivariant Heegaard Floer cohomology of its branched double cover, defined by Lipschitz, Hendricks, and Sarkar. We prove the naturality and functoriality of equivariant Heegaard Floer cohomology for branched double covers of S3 a…
In this paper, we establish a general relationship between the nonvanishing of GW invariants with the existence of the closed orbits of a Hamiltonian system. As an application, we completely solved the stabilized Weinstein conjecture.
We show that there exists a Legendrian knot with maximal Thurston-Bennequin invariant whose contact homology is trivial. We also provide another Legendrian knot which has the same knot type and classical invariants but nonvanishing contact homology.
The study explores geometric properties of hyperbolic cohomology classes on Kähler manifolds.
problem Understanding the geometric effects of hyperbolic cohomology classes on Kähler manifolds.
method Introducing Kähler topologically hyperbolic manifolds and proving spectral gap theorems for positive holomorphic Hermitian vector bundles.
result Kähler topologically hyperbolic manifolds are not uniruled nor bimeromorphic to compact Kähler manifolds with trivial first real Chern class.
We show that the boundaries of thin strongly pseudoconvex Grauert tubes, with respect to the Guillemin-Stenzel Kähler metric canonically associated with the Poincaré metric on closed hyperbolic real-analytic surfaces, has nowhere vanishing Cartan CR-curvature. This result provides a wealth of examples of compact 3-di…
We consider four-dimensional vacuum spacetimes which admit a nonvanishing spacelike Killing field. The quotient with respect to the Killing action is a three-dimensional quotient spacetime (M,g). We establish several results regarding maximal hypersurfaces (spacelike hypersurfaces of zero mean curvature) in such quot…
We prove that symplectic 4-manifolds with b1=0 and b+>1 have nonvanishing Donaldson invariants, and that the canonical class is always a basic class. We also characterize in many situations the basic classes of a Lefschetz fibration over the sphere which evaluate maximally on a generic fiber.
The paper introduces a new flow for Legendrian curves in Sasakian sub-Riemannian 3-manifolds.
problem Investigating the behavior of Legendrian curves in specific geometric settings.
method Introducing and analyzing a modified inverse mean curvature flow for Legendrian curves in Sasakian sub-Riemannian 3-manifolds.
result The flow preserves the Legendrian condition and increases the length of curves, with specific asymptotic behaviors.
We show that a compact manifold admitting a Killing foliation with positive transverse curvature fibers over finite quotients of spheres or weighted complex projective spaces, provided that the singular foliation defined by the closures of the leaves has maximal dimension. This result is obtained by deforming the folia…
The main theorem of the paper shows that a smooth manifold which is homeomorphic to S^2xS^2 and has nonvanishing Ozsvath-Szabo invariant does not admit a perfect Morse function. I am withdrawing the paper because it is unclear to me if such a manifold exists.
In this paper we deal with quadratic metric-affine gravity, which we briefly introduce, explain and give historical and physical reasons for using this particular theory of gravity. Further, we introduce a generalisation of well known spacetimes, namely pp-waves. A classical pp-wave is a 4-dimensional Lorentzian spacet…
In this paper, we construct a canonical grading on bordered Heegaard Floer homology by homotopy classes of nonvanishing vector fields. This grading is a generalization of our construction of an absolute grading on Heegaard Floer homology and it extends the well-known grading with values in a noncommutative group define…
We show that a finite type duality group of dimension d>2 is the fundamental group of a (d+3)-manifold with rationally acyclic universal cover. We use this to find closed manifolds with rationally acyclic universal cover and some nonvanishing L2-Betti numbers outside the middle dimension, which contradicts a rat…