On flagged KK-theoretic symmetric polynomials

We provide a fermionic description of flagged skew Grothendieck polynomials, which can be seen as a $K$-theoretic counterpart of flagged skew Schur polynomials. Our proof relies on the Jacobi-Trudi type formula established by Matsumura. This result generalizes the author's previous works on a fermionic description of skew Grothendieck polynomials and multi-Schur functions.Comment: 8page