Hamiltonian Gromov–Witten Invariants on C~(n+1) with S~1-action

Consider a Hamiltonian action of S~1 on(C~(n+1), ω_(std)), we shown that the Hamiltonian Gromov–Witten invariants of it are well-defined. After computing the Hamiltonian Gromov–Witten invariants of it, we construct a ring homomorphism from H*_(S~1,CR)(X, R) to the small orbifold quantum cohomology of X //_τ S~1 and obtain a simpler formula of the Gromov–Witten invariants for weighted projective space.     

Scattering Diagrams,Sheaves, and Curves

We review the recent proof of the N. Takahashi's conjecture on genus 0 Gromov–Witten invariants of(P~2, E), where E is a smooth cubic curve in the complex projective plane P~2. The main idea is the use of the algebraic notion of scattering diagram as a bridge between the world of Gromov–Witten invariants of(P~2, E) and the world of moduli spaces of coherent sheaves on P~2. Using this bridge, the N. Takahashi's conjecture can be translated into a manageable question about moduli spaces of coherent sheaves on P~2. This survey is based on a three hours lecture series given as part of the Beijing–Zurich moduli workshop in Beijing, 9–12 September 2019.     

Orbifold Gromov–Witten Invariants of Weighted Blow-up at Smooth Points

In this paper, one considers the change of orbifold Gromov–Witten invariants under weighted blow-up at smooth points. Some blow-up formula for Gromov–Witten invariants of symplectic orbifolds is proved. These results extend the results of manifolds case to orbifold case.     

Topological recursion relations from Pixton relations

We propose an algorithm to derive tautological relations from Pixton relations. We carry out this algorithm explicitly to derive some results in genus 0, 1, 2, 3 and analyze the possibility to generalize to higher genera. As an application, some results about reconstruction of Gromov–Witten invariants can be derived.     

Chamber Structure for Some Equivariant Relative Gromov–Witten Invariants of P~1 in Genus 0

In this paper, we study genus 0 equivariant relative Gromov–Witten invariants of P1 whose corresponding relative stable maps are totally ramified over one point. For fixed number of marked points, we show that such invariants are piecewise polynomials in some parameter space. The parameter space can then be divided into polynomial domains, called chambers. We determine the difference of polynomials between two neighbouring chambers. In some special chamber, which we called the totally negative chamber, we show that such a polynomial can be expressed in a simple way. The chamber structure here shares some similarities to that of double Hurwitz numbers.     

A Quantum Modification of Relative Chen–Ruan Cohomology

In this paper, by using the de Rham model of Chen–Ruan cohomology, we define the relative Chen–Ruan cohomology ring for a pair of almost complex orbifold(G, H) with H being an almost sub-orbifold of G. Then we use the Gromov–Witten invariants ofG, the blow-up of G along H,to give a quantum modification of the relative Chen–Ruan cohomology ring H*CR(G, H) when H is a compact symplectic sub-orbifold of the compact symplectic orbifold G.     

Quantum hyperbolic invariants for diffeomorphisms of small surfaces

An earlier article [Bonahon, F., Liu, X. B.: Representations of the quantum Teichmüller space and invariants of surface diffeomorphisms. Geom. Topol., 11, 889-937 (2007)] introduced new invariants for pseudo-Anosov diffeomorphisms of surface, based on the representation theory of the quantum Teichmu¨ller space. We explicitly compute these quantum hyperbolic invariants in the case of the 1-puncture torus and the 4-puncture sphere.     

Stability of Navier–Stokes System with Singular External Force in Fourier–Herz Space

We prove the asymptotic properties of the solutions to the 3D Navier–Stokes system with singular external force, by making use of Fourier localization method, the Littlewood–Paley theory and some subtle estimates in Fourier–Herz space. The main idea of the proof is motivated by that of Cannone et al. [J. Differential Equations, 314, 316–339(2022)]. We deal either with the nonstationary problem or with the stationary problem where solution may be singular due to singular external force. In this p...     

Index computations in FJRW theory

We compute the index of the real Cauchy–Riemann operator defined in FJRW theory in case of the smooth metric.For the cylindrical metric,we study the relation between the index of the linearized operator of Witten map and weights in weighted Sobolev spaces.     

Note on a Conjecture of Gopakumar-Vafa

We rephrase the Gopakumar-Vafa conjecture on genus zero Gromov-Witten invariants of Calabi-Yau threefolds in terms of the virtual degree of the moduli of pure dimension one stable sheaves and investigate the conjecture for K3 fibred local Calabi-Yau threefolds.     

THE NON-CUTOFF BOLTZMANN EQUATION WITH POTENTIAL FORCE IN THE WHOLE SPACE

This paper is concerned with the non-cutoff Boltzmann equation for full-range interactions with potential force in the whole space. We establish the global existence and optimal temporal convergence rates of classical solutions to the Cauchy problem when initial data is a small perturbation of the stationary solution. The analysis is based on the timeweighted energy method building also upon the recent studies of the non-cutoff Boltzmann equation in [1–3, 15] and the non-cutoff Vlasov-Poisson-Boltzmann system [6].     

A note on Marino-Vafa formula

Hodge integrals over moduli spaces of curves appear naturally during the localization procedure in computation of Gromov-Witten invariants. A remarkable formula of Marino-Vafa expresses a generation function of Hodge integrals via some combinatorial and algebraic data seemingly unrelated to these apriori algebraic geometric objects. We prove in this paper by directly expanding the formula and estimating the involved terms carefully that except a specific type all the other Hodge integrals involving up to three Hodge classes can be calculated from this formula. This implies that amazingly rich information about moduli spaces and Gromov-Witten invariants is encoded in this complicated formula. We also give some low genus examples which agree with the previous results in literature. Proofs and calculations are elementary as long as one accepts Mumford relations on the reductions of products of Hodge classes.     

A Survey on Mixed Spin P-Fields

The mixed spin P-fields (MSP for short) theory sets up a geometric platform to relate Gromov-Witten invariants of the quintic three-fold and Fan-Jarvis-Ruan-Witten invariants of the quintic polynomial in five variables.It starts with Wittens vision and the P-fields treatment of GW invariants and FJRW invariants.Then it briefly discusses the master space technique and its application to the set-up of the MSP moduli.Some key results in MSP theory are explained and some examples are provided.     

The Aubry Set and Mather Set in the Embedded Contact Hamiltonian System

We embed the Aubry set and Mather set in the Tonelli Hamiltonian system to the contact Hamiltonian system. We find the embedded Aubry set is the set of non-wandering points of the contact Hamiltonian system and the Mather set is the support of set of the invariant Borel probability measures for the contact Euler–Lagrange flow. From this viewpoint, we can conclude that Aubry set and Mather set are symplectic invariants.     

On Fridman Invariants and Generalized Squeezing Functions*

In this paper, the authors introduce the notion of generalized squeezing function and study the basic properties of generalized squeezing functions and Fridman invariants.They also study the comparison of these two invariants, in terms of the so-called quotient invariant.     

A Remark on Leray's Problem on Stationary Navier–Stokes Flows with Large Fluxes in Infinite Cylindrical Domains

We consider Leray's problem on stationary Navier–Stokes flows with arbitrary large fluxes in an unbounded cylinder with several exits to infinity. For a stationary Navier–Stokes flow with large fluxes in the unbounded cylinder, we prove that, if the difference between the pressure of the main flow and the pressure of the Poiseuille flow with the same flux in a branch of the cylinder remains bounded at |x| →∞, then the flow behaves at infinity of the branch like the Poiseuille flow.     

一类连续时间参数的随机图过程的平稳分布

A continuous-time random graph process with state space consisting of the simple and directed graphs on N vertices is introduced.We obtain the stationary distribution of the process under different couditions and prove that the stationary distribution is unique.     

The Bott–Chern and Aeppli Cohomologies of Complex Structures on S~3×S~3

We calculate the dimensions of Bott–Chern and Aeppli cohomologies associated to a complex structure on S~3×S~3.We express them in terms mainly of Hogde numbers.     

THE STABILITY OF STATIONARY SOLUTION FOR OUTFLOW PROBLEM ON THE NAVIER-STOKES-POISSON SYSTEM

In this article, we are concerned with the stability of stationary solution for outflow problem on the Navier-Stokes-Poisson system. We obtain the unique existence and the asymptotic stability of stationary solution. Moreover, the convergence rate of solution towards stationary solution is obtained. Precisely, if an initial perturbation decays with the algebraic or the exponential rate in space, the solution converges to the corresponding stationary solution as time tends to infinity with the algebraic or the exponential rate in time. The proof is based on the weighted energy method by taking into account the effect of the self-consistent electric field on the viscous compressible fluid.     

Gradient estimates for parabolic equations in generalized weighted Morrey spaces

We consider the Cauchy–Dirichlet problem for linear divergence form parabolic operators in bounded Reifenberg flat domain.The coefficients supposed to be only measurable in one of the space variables and small BMO with respect to the others.We obtain Calderón–Zygmund type estimate for the gradient of the solution in generalized weighted Morrey spaces with Muckenhoupt weight.