形式为 a n + 1 =pa n + s/qa n + r , p,q,r,s ∈ R的线性分式递推数列是高中数学数列部分常见题型。本文从初等数学的角度:化归思想,取倒数,转化等差(或等比)数列,给出形式为a n + 1 =pa n + s/qa n + r的线性分式递推数列的通项公式...形式为 a n + 1 =pa n + s/qa n + r , p,q,r,s ∈ R的线性分式递推数列是高中数学数列部分常见题型。本文从初等数学的角度:化归思想,取倒数,转化等差(或等比)数列,给出形式为a n + 1 =pa n + s/qa n + r的线性分式递推数列的通项公式及周期存在的判定,并举例说明其价值。展开更多
Hodge integrals over moduli space of stable curves play an important roles in understanding the topological properties of moduli space. ELSV formula connects the Hodge integrals with Hurwitz numbers, and the generatin...Hodge integrals over moduli space of stable curves play an important roles in understanding the topological properties of moduli space. ELSV formula connects the Hodge integrals with Hurwitz numbers, and the generating function of Hurwitz numbers satisfies the cut-and-join equation. Therefore, it is natural to consider how to use the cut-and-join equation for Hurwitz numbers to compute Hodge integrals which appear in ELSV formula. In this paper, at first, we will review the method introduced in Goulden et al.'s paper to get the λg conjecture for Hodge integral. Through some variables transformation, the generating function of Hurwitz number becomes a symmetric polynomial which satisfies a symmetrized cut-and-join equation. By comparing the coefficients of the lowest degree term of both sides in this equation, we can get the ,λg conjecture. Then, in a similar way, we obtain our main result in this paper: a recursive formula for Hodge integral of type contains only one ,λg-l-class. We also point out that our results are closely related to the degree 0 Virasoro conjecture for a curve.展开更多
文摘形式为 a n + 1 =pa n + s/qa n + r , p,q,r,s ∈ R的线性分式递推数列是高中数学数列部分常见题型。本文从初等数学的角度:化归思想,取倒数,转化等差(或等比)数列,给出形式为a n + 1 =pa n + s/qa n + r的线性分式递推数列的通项公式及周期存在的判定,并举例说明其价值。
文摘Hodge integrals over moduli space of stable curves play an important roles in understanding the topological properties of moduli space. ELSV formula connects the Hodge integrals with Hurwitz numbers, and the generating function of Hurwitz numbers satisfies the cut-and-join equation. Therefore, it is natural to consider how to use the cut-and-join equation for Hurwitz numbers to compute Hodge integrals which appear in ELSV formula. In this paper, at first, we will review the method introduced in Goulden et al.'s paper to get the λg conjecture for Hodge integral. Through some variables transformation, the generating function of Hurwitz number becomes a symmetric polynomial which satisfies a symmetrized cut-and-join equation. By comparing the coefficients of the lowest degree term of both sides in this equation, we can get the ,λg conjecture. Then, in a similar way, we obtain our main result in this paper: a recursive formula for Hodge integral of type contains only one ,λg-l-class. We also point out that our results are closely related to the degree 0 Virasoro conjecture for a curve.