• Journal of the Korean Mathematical Society
• /
• v.58 no.1
• /
• pp.219-236
• /
• 2021

Let �� be a weighted projective line defined over the algebraic closure $k={\bar{\mathbb{F}}}_q$ of the finite field ��q and σ be a weight permutation of ��. By folding the category coh-�� of coherent sheaves on �� in terms of the Frobenius twist functor induced by σ, we obtain an ��q-category, denoted by coh-(��, σ; q). We then prove that coh-(��, σ; q) is derived equivalent to the valued canonical algebra associated with (��, σ).

• Bulletin of the Korean Mathematical Society
• /
• v.52 no.6
• /
• pp.2047-2069
• /
• 2015

The coset diagrams are composed of fragments, and the fragments are further composed of circuits at a certain common point. A condition for the existence of a certain fragment ${\gamma}$ of a coset diagram in a coset diagram is a polynomial f in ${\mathbb{Z}}$[z]. In this paper, we answer the question: how many polynomials are obtained from the fragments, evolved by joining the circuits (n, n) and (m, m), where n < m, at all points.