Study inverse problems for twisted geodesic flows on manifolds.
problem Understanding inverse problems for twisted geodesic flows.
method Generalized ray transforms and tensor tomography.
result New insights into rigidity problems for twisted geodesic flows.
Study proves uniqueness for ray transform on surfaces with obstacles.
problem Uniqueness of functions and 1-forms on surfaces with reflecting obstacles.
method Broken ray transform on twisted geodesics with nonpositive curvature and reflecting boundary.
result Proves uniqueness result for sums of functions and 1-forms.
Proves geodesic connections on 2-torus without invariant tori.
problem Existence of geodesic connections on 2-torus without invariant tori.
method Uses J. Mather's result on connecting orbits for monotone twist maps.
result Proves existence of connecting geodesics on unit tangent bundle of 2-torus.
The paper shows how different geodesic flows on surfaces can be mapped to each other.
problem Comparing pseudo-Anosov maps from various Birkhoff sections of a geodesic flow.
method Identifying canonical surfaces and expressing first-return maps as compositions of Dehn twists.
result First-return maps from different Birkhoff sections are equivalent and can be expressed using a fixed set of Dehn twists.
Characterizes parabolic flute surfaces with specific parameters.
problem Characterizing flute surfaces with ergodic geodesic flow.
method Extending results on Fenchel-Nielsen coordinates and analyzing twist parameters.
result Characterizes parabolic flute surfaces with twist parameters in {0,1/2}.
Researchers prove twists can make surfaces parabolic even with large cuff lengths.
problem Making surfaces parabolic with large cuff lengths and twists.
method Choosing lengths and applying twists to make surfaces parabolic.
result For any sequence of positive numbers, there is a choice of lengths such that twists make the surface parabolic.
Study of twisted Ruelle zeta function on hyperbolic manifolds and its relation to analytic torsion.
problem Analyzing the twisted Ruelle zeta function on hyperbolic manifolds.
method Investigating the twisted Ruelle zeta function associated with geodesic flow and acyclic representations.
result The twisted Ruelle zeta function equals the square of the refined analytic torsion multiplied by an exponential involving the eta invariant.
Let (X,ω) be a compact connected Kähler manifold and denote by (Ep,dp) the metric completion of the space of Kähler potentials Hω with respect to the Lp-type path length metric dp. First, we show that the natural analytic extension of the (twisted) Mabuchi K-energy to Ep is …
We show that if K: P \to R is an autonomous Hamiltonian on a symplectic manifold (P,Ω) which attains 0 as a Morse-Bott nondegenerate minimum along a symplectic submanifold M, and if c_1(TP)|_M vanishes in real cohomology, then the Hamiltonian flow of K has contractible periodic orbits with bounded period on all suffici…
We use ending laminations for Weil-Petersson geodesics to establish that bounded geometry is equivalent to bounded combinatorics for Weil-Petersson geodesic segments, rays, and lines. Further, a more general notion of non-annular bounded combinatorics, which allows arbitrarily large Dehn-twisting, corresponds to an equ…
We study the twisted Ruelle zeta function ζX(s) for smooth Anosov vector fields X acting on flat vector bundles over smooth compact manifolds. In dimension 3, we prove Fried conjecture, relating Reidemeister torsion and ζX(0). In higher dimensions, we show more generally that ζX(0) is locally constant with…
Study parabolicity of Riemann surfaces via Fenchel-Nielsen parameters.
problem Determine conditions for a Riemann surface to be of parabolic type.
method Use Fenchel-Nielsen parameters and non-standard half-collars to study parabolicity.
result Obtain sufficient conditions for parabolicity in terms of Fenchel-Nielsen parameters.
The paper proves exponential mixing for hyperbolic manifolds, with applications to geodesic holonomy.
problem Establishing exponential mixing for frame flows on hyperbolic manifolds.
method Using spectral bounds on transfer operators twisted by holonomy, building on Dolgopyat's method.
result Exponential mixing of frame flows for convex cocompact hyperbolic manifolds.
Study geodesic flow on symmetric surfaces to determine parabolic type.
problem Determine conditions for a Riemann surface to be of parabolic type.
method Analyze Fenchel-Nielsen coordinates and covering group properties.
result Conditions for a surface to be parabolic are equivalent to specific properties of its Fenchel-Nielsen coordinates.
Study of Veech surfaces and their twist tori on moduli spaces of abelian differentials.
problem Distribution of expanding twist tori on moduli spaces of translation surfaces.
method Analysis of Teichmüller geodesic flow and horocycle flow on Veech surfaces.
result Expanding twist tori become dense in the limiting locus as time goes to infinity.
The study finds infinitely many twist knot complements with totally geodesic surfaces.
problem Finding infinitely many twist knot complements with a specific number of totally geodesic surfaces.
method Using a family of twist knot complements and their dihedral covers, the authors construct examples of hyperbolic 3-manifolds with totally geodesic surfaces.
result The construction of infinitely many non-commensurable hyperbolic 3-manifolds with exactly k totally geodesic surfaces for any positive integer k.
The paper studies the twisted Calabi flow on Kähler manifolds.
problem Analyzing the behavior of the twisted Calabi flow on compact Kähler manifolds.
method Establishing convexity, proving short-time existence, and demonstrating stability of the flow.
result The stability of the twisted Calabi flow near twisted constant scalar curvature Kähler metrics.
We introduce a new object, the dynamical torsion, which extends the potentially ill-defined value at 0 of the Ruelle zeta function of a contact Anosov flow twisted by an acyclic representation of the fundamental group. We show important properties of the dynamical torsion: it is invariant under deformations among con…
Study of twisted Calabi flow connecting J-flow and Calabi flow on Kähler manifolds.
problem Existence and convergence of twisted Calabi flow on compact Kähler manifolds.
method Analysis of a family of twisted Calabi flows connecting J-flow and Calabi flow, showing long-time existence and convergence to cscK metrics.
result Long-time existence and convergence of twisted Calabi flow to cscK metrics, implying openness of continuity method.
Paper studies convergence of Yang-Mills-Higgs flow on Kähler manifolds.
problem Analyzing convergence of Yang-Mills-Higgs flow for twisted Higgs pairs.
method Proves convergence to a reflexive twisted Higgs sheaf outside a closed subset.
result Limiting twisted Higgs sheaf is isomorphic to the double dual of graded twisted Higgs sheaves.
In this paper we present a certain class of geodesic vector fields of the double-twisted product R X R. Some examples of totally geodesic foliations are given.
The study examines Heegaard splittings defined by Dehn twists and finds hyperbolic metrics with specific geodesic lengths.
problem Characterizing Heegaard splittings defined by Dehn twists and their geometric properties.
method Examining Heegaard splittings of genus g≥3 defined by the n-th power of a Dehn twist along a pared acylindrical curve. result For n≥14, the Heegaard splitting has a hyperbolic metric with a closed geodesic of length between 0.7/(n2g2) and 34.3/n2. We show that a small neighborhood of a closed symplectic submanifold in a geometrically bounded aspherical symplectic manifold has non-vanishing symplectic homology. As a consequence, we establish the existence of contractible closed characteristics on any thickening of the boundary of the neighborhood. When applied to…
For φ a metric on the anticanonical bundle, −KX, of a Fano manifold X we consider the volume of X ∫Xe−φ. We prove that the logarithm of the volume is concave along continuous geodesics in the space of positively curved metrics on −KX and that the concavity is strict unless the geodesic comes f…
In this paper we study a generalization of the Kahler-Ricci flow, in which the Ricci form is twisted by a closed, non-negative (1,1)-form. We show that when a twisted Kahler-Einstein metric exists, then this twisted flow converges exponentially. This generalizes a result of Perelman on the convergence of the Kahler-Ric…
We introduce a pair of isospectral but non-isometric compact flat 3-manifolds called Tetra (a tetracosm) and Didi (a didicosm). The closed geodesics of Tetra and Didi are very different. Where Tetra has two quarter-twisting geodesics of the shortest length, Didi has four half-twisting geodesics. Nevertheless, these spa…
In this paper, we study the long-term behavior of the conical Kähler-Ricci flow on Fano manifold M. First, based on our work of locally uniform regularity for the twisted Kähler-Ricci flows, we obtain a long-time solution to the conical Kähler-Ricci flow by limiting a sequence of these twisted flows. Second, we study…
The main theme of this paper is a relative version of the almost existence theorem for periodic orbits of autonomous Hamiltonian systems. We show that almost all low levels of a function on a geometrically bounded symplectically aspherical manifold carry contractible periodic orbits of the Hamiltonian flow, provided th…
Study of gyroscopic Chaplygin systems and magnetic flows on spheres.
problem Integrability and Hamiltonization of magnetic geodesic flows on spheres.
method Analysis of gyroscopic Chaplygin systems with magnetic forces, Hamiltonization, invariant measure existence.
result Integrable magnetic geodesic flows on spheres Sn−1 for n>3. 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.
Paper shows regularizing flow for conical Kähler-Ricci equations.
problem Regularizing property of conical Kähler-Ricci flow.
method Regularizing property of the twisted conical Kähler-Ricci flow from a positive closed current with zero Lelong number.
result Extends regularizing property to conical singularity case.
The paper proves uniqueness of closed timelike geodesics on de-Sitter tori with one singularity.
problem Uniqueness of closed timelike geodesics on de-Sitter tori with one singularity.
method Introduced the notion of timelike marked length spectrum and constructed length-twist coordinates.
result Uniqueness of closed timelike geodesics in their free homotopy class.
We prove a uniform isoperimetric inequality for all time along the twisted Kähler-Ricci flow on Fano manifolds.
We relate trimmed sums of twists in cylinders along a typical Teichmuller geodesic to the area Siegel-Veech constant.
Twisted U- and twisted U/K-hierarchies are soliton hierarchies introduced by Terng to find higher flows of the generalized sine-Gordon equation. Twisted O(J)×O(J)O(J,J)-hierarchies are among the most important classes of twisted hierarchies. In this paper, interesting first and higher flows of twi…
In the first part of this work we explore the geometry of infinite type surfaces and the relationship between its convex core and space of ends. In particular, we show that a geodesically complete hyperbolic surface is made up of its convex core with funnels attached along the simple closed geodesic components and half…
Study of J-flow on Kähler manifolds confirms energy properness.
problem Properness of Mabuchi K-energy on Kähler manifolds.
method Degenerate twisted J-flow on compact Kähler manifolds.
result Flow converges to weak solution of degenerate twisted J-equation.
We consider the gradient flow of the Yang-Mills-Higgs functional of twist Higgs pairs on a Hermitian vector bundle (E,H0) over a Riemann surface X. It is already known the gradient flow with initial data (A0,φ0) converges to a critical point (A∞,φ∞) of this functional. Using a modified Chern-Wei…
The paper connects geodesic flows, hyperbolic geodesics, and stable ergodicity.
problem Understanding conditions for geodesic flows to be Anosov and ergodic.
method Analyzing Finsler and Riemannian metrics on surfaces, using recent results.
result Geodesic flows on surfaces are C2 stably ergodic if and only if they are Anosov. Proves stability of geodesic flows on closed surfaces.
problem Stability of geodesic flows on closed surfaces.
method Generic Riemannian metrics and Reeb flows.
result Proves C2-stability conjecture for geodesic flows. Geometrically, twist numbers on punctured tori are dense and non-continuous.
problem Understanding twist numbers on hyperbolic punctured tori.
method Hyperbolic geometry and Farey graph analysis.
result The graph of twist numbers is dense in [0,1]x[0,1].
Homoclinic orbits found in geodesic flows on surfaces.
problem Existence of homoclinic orbits in geodesic flows.
method Kupka-Smale metric on closed surfaces.
result Homoclinic orbits for all hyperbolic geodesics.
Study of curve shortening flow for twisted curves, defining curvature-torsion entropy.
problem Understanding the behavior of curves with curvature and torsion under curve shortening flow.
method Defined curvature-torsion entropy to analyze the flow of twisted curves.
result Curved curves under curve shortening flow either develop inflection points or exhibit highly irregular singularities.
Proves robust transitivity for geodesic flows from metrics with conjugate points.
problem Transitivity of geodesic flows from metrics with conjugate points.
method General criterion for robust transitivity of partially hyperbolic geodesic flows.
result First example of a C2 open set of Riemannian metrics with conjugate points and transitive geodesic flow. Anosov geodesic flow proven in non-compact manifolds with negative curvature.
problem Proving Anosov geodesic flow in non-compact manifolds with negative curvature.
method Proving the geodesic flow is Anosov by showing average sectional curvature is negative and uniformly away from zero.
result Constructed a non-compact manifold with Anosov geodesic flow.
In this paper, by limiting twisted conical Kähler-Ricci flows, we prove the long-time existence and uniqueness of cusp Kähler-Ricci flow on compact Kähler manifold M which carries a smooth hypersurface D such that the twisted canonical bundle KM+D is ample. Furthermore, we prove that this flow converge to a uniq…
Study geodesic flows on cones over Riemannian manifolds, showing superintegrability.
problem Behavior of geodesics on cones over arbitrary Riemannian manifolds.
method Show existence of first integrals uniquely determining geodesics.
result Geodesic flow on cones is superintegrable and Liouville--Arnold integrable for non-radial trajectories.
Two Riemannian manifolds are said to have Ck-conjugate geodesic flows if there exist an Ck diffeomorphism between their unit tangent bundles which intertwines the geodesic flows. We obtain a number of rigidity results for the geodesic flows on compact 2-step Riemannian nilmanifolds: For generic 2-step nilmanifold…