9 papers
Monotone maximum partial-twuality widths of vf-safe delta-matroids
Qi Yan, Zhao Zhao
For a delta-matroid, the maximum twist width theorem states that the maximum width over all twists can be reached along a non-decreasing sequence of intermediate twist widths. In t…
Partial-twuality polynomial interpolation for binary delta-matroids
Zhuo Li, Qi Yan, Xian'an Jin
Gross, Mansour and Tucker introduced the partial-twuality polynomials for ribbon graphs and investigated the interpolation property of these polynomials. The ribbon group generated…
Recurrence and coefficient inequality for the partial Petrial polynomial of graphs
Ruiqing Feng, Xia Guo, Qi Yan
The partial Petrial polynomial of a ribbon graph, introduced by Gross, Mansour and Tucker, enumerates partial Petrials by Euler genus. Recently, Deng, Jin and Yan defined an analog…
Twist polynomial interpolation for binary delta-matroids
Zhao Zhao, Qi Yan
Gross, Mansour and Tucker introduced the partial-dual polynomial of a ribbon graph and asked under what conditions such a polynomial is even-interpolating, odd-interpolating, or bo…
Partial-twuality polynomials of matrices
Qingying Deng, Xian'an Jin, Qi Yan
The study of partial-twuality polynomials originates from the classical operations of geometric duality and Petrie duality on cellularly embedded graphs. These involutions generate…
On the maximum twist width of delta-matroids
Xian'an Jin, Zhuo Li, Qi Yan +1
For a ribbon graph , let denote its Euler genus. Recently, Chen, Gross and Tucker [J. Algebraic Combin. 63 (2026) 13] derived a formula for the maximum partial-dual Eule…