3 citations · 7 across the 8 of their papers we have counts for
9 papers
An alternative construction of zip period maps for Shimura varieties
Qijun Yan
Let be the special fibre of a Shimura variety of Hodge type, with good reduction at a place above . We give an alternative construction of the zip period map for , which…
Twist polynomials of delta-matroids
Qi Yan, Xian'an Jin
Recently, Gross, Mansour and Tucker introduced the partial duality polynomial of a ribbon graph and posed a conjecture that there is no orientable ribbon graph whose partial dualit…
The Ihara-zeta function and the spectrum of the join of two semi-regular bipartite graphs
Xiaotong Li, Xian'an Jin, Qi Yan
In this paper, using matrix techniques, we compute the Ihara-zeta function and the number of spanning trees of the join of two semi-regular bipartite graphs. Furthermore, we show t…
Partial-dual genus polynomials and signed intersection graphs
Qi Yan, Xian'an Jin
Recently, Gross, Mansour and Tucker introduced the partial-dual genus polynomial of a ribbon graph as a generating function that enumerates the partial duals of the ribbon graph by…
Excluded checkerboard colourable ribbon graph minors
Xia Guo, Xian'an Jin, Qi Yan
In this paper, we first introduce the notions of checkerboard colourable minors for ribbon graphs motivated by the Eulerian ribbon graph minors, and two kinds of bipartite minors f…
Counterexamples to conjectures by Gross, Mansour and Tucker on partial-dual genus polynomials of ribbon graphs
Qi Yan, Xian'an Jin
Gross, Mansour and Tucker introduced the partial-dual orientable genus polynomial and the partial-dual Euler genus polynomial. They computed these two partial-dual genus polynomial…