In this paper, we construct toric data of moduli space of quasimaps of degree 𝑑 from ℙ¹ with two marked points to weighted projective space ℙ(1, 1, 1, 3). With this result, we prove that the moduli space is a compact toric orbifold. We also determine its Chow ring. Moreover, we give a proof of the conjecture proposed by Jinzenji that a series of intersection numbers of the moduli spaces coincides with expansion coefficients of inverse function of −log(𝑗(𝜏)).

Relations between the hypergeometric function with a large parameter and Borel sums of WKB solutions of the hypergeometric differential equation with the large parameter are established. The confluent hypergeometric function is also investigated from the viewpoint of exact WKB analysis. As applications, asymptotic expansion formulas for those classical special functions with respect to parameters are obtained.

The notion of extriangulated category was introduced by Nakaoka and Palu giving a simultaneous generalization of exact categories and triangulated categories. Our first aim is to provide an extension to extriangulated categories of Auslander's formula: for some extriangulated category 𝒞, there exists a localization sequence def 𝒞 → mod 𝒞 → lex 𝒞, where lex 𝒞 denotes the full subcategory of finitely presented left exact functors and def 𝒞 the full subcategory of Auslander's defects. Moreover we provide a connection between the above localization sequence and the Gabriel–Quillen embedding theorem. As an application, we show that the general heart construction of a cotorsion pair (𝒰, 𝒱) in a triangulated category, which was provided by Abe and Nakaoka, is the same as the construction of a localization sequence def 𝒰 → mod 𝒰 → lex 𝒰.

This paper is concerned with supersolutions to parabolic equations with space-dependent diffusion coefficients. Given the behavior of the diffusion coefficient with polynomial order at spatial infinity, a family of supersolutions with slowly decaying property at spatial infinity is provided. As a first application, weighted 𝐿² type decay estimates for the initial-boundary value problem of the parabolic equation are proved. The second application is the study of the exterior problem of wave equations with space-dependent damping terms. By using supersolution provided above, energy estimates with polynomial weight and diffusion phenomena are shown. There is a slight improvement compared to the previous work about the assumption of the initial data.

We introduce finite and symmetric Mordell–Tornheim type of multiple zeta values and give a new approach to the Kaneko–Zagier conjecture stating that the finite and symmetric multiple zeta values satisfy the same relations.

We construct a class of iterated stochastic integrals with respect to Brownian motion on an abstract Wiener space which allows for the definition of Brownian motions on a general class of infinite-dimensional nilpotent Lie groups based on abstract Wiener spaces. We then prove that a Cameron–Martin type quasi-invariance result holds for the associated heat kernel measures in the non-degenerate case, and give estimates on the associated Radon–Nikodym derivative. We also prove that a log Sobolev estimate holds in this setting.

Let (𝑢, 𝑣) be a solution to a semilinear parabolic system

(P)    \begin{cases}𝜕_𝑡 𝑢 = 𝐷₁ Δ 𝑢+𝑣^𝑝 in 𝐑^𝑁 ×(0, 𝑇),   𝜕_𝑡 𝑣 = 𝐷₂ Δ 𝑣+𝑢^𝑞 in 𝐑^𝑁 ×(0, 𝑇),   𝑢, 𝑣 ≥ 0 in 𝐑^𝑁 ×(0, 𝑇),   (𝑢(⋅, 0), 𝑣(⋅, 0)) = (𝜇, 𝜈) in 𝐑^𝑁, \end{cases}

where 𝑁 ≥ 1, 𝑇 > 0, 𝐷₁ > 0, 𝐷₂ > 0, 0 < 𝑝 ≤ 𝑞 with 𝑝𝑞 > 1 and (𝜇, 𝜈) is a pair of Radon measures or nonnegative measurable functions in 𝐑^𝑁. In this paper we study qualitative properties of the initial trace of the solution (𝑢, 𝑣) and obtain necessary conditions on the initial data (𝜇, 𝜈) for the existence of solutions to problem (P).

We introduce coordinate systems to the Teichmüller space of the twice-punctured torus and give matrix representations for the points of Teichmüller space. The coordinate systems allow representation of the mapping class group of the twice punctured torus as a group of rational transformations and provide several applications to the mapping class group and also to Kleinian groups.

We consider the multicanonical systems |𝑚𝐾_𝑆| of quasi-elliptic surfaces with Kodaira dimension 1 in characteristic 2. We show that for any 𝑚 ≥ 6 |𝑚𝐾_𝑆| gives the structure of quasi-elliptic fiber space, and 6 is the best possible number to give the structure for any such surfaces.

We answer a conjecture raised by Caucher Birkar of singularities of weighted blowups of 𝔸^𝑛 for 𝑛 ≤ 3.

In this paper, we derive an upper bound for higher eigenvalues of the normalized Laplace operator associated with a symmetric finite graph in terms of lower eigenvalues.

We present an algorithm that takes as input any element 𝐵 of the loop braid group and constructs a polynomial 𝑓 : ℝ⁵ → ℝ² such that the intersection of the vanishing set of 𝑓 and the unit 4-sphere contains the closure of 𝐵. The polynomials can be used to create real analytic time-dependent vector fields with zero divergence and closed flow lines that move as prescribed by 𝐵. We also show how a family of surface braids in ℂ ×𝑆¹ ×𝑆¹ without branch points can be constructed as the vanishing set of a holomorphic polynomial 𝑓 : ℂ³ → ℂ on ℂ ×𝑆¹ ×𝑆¹ ⊂ ℂ³. Both constructions allow us to give upper bounds on the degree of the polynomials.