A quotient of Fomin-Kirillov Algebra and q-Lucas polynomial

Abstract

We introduce a quotient of Fomin-Kirillov algebra $FK(n)$ denoted $\overline{FK}_{C_n}(n)$, over the ideal generated by the edges of a complete graph on n vertexes that are missing in the $n$-cycle graph $C_n$. For this quotient algebra $\overline{FK}_{C_n}(n)$, we show that the basis is in one-to-one correspondence with the set of matchings in an $n$-cycle graph. We also prove that the dimension of $\overline{FK}_{C_n}(n)$ equals the Lucas Number $L_n$ and its Hilbert series is $q$-Lucas polynomial. We find the character map of this quotient algebra over Dihedral group $D_n$.