Koushik Brahma

activity

20192026

collaborators

9 papers

math.RT2026

Minuscule Relations in Quantum $K$ -Theory of Flag Varieties

Koushik Brahma, Yicen Huang, Takeshi Ikeda +2

We study the quantum $K$ -theory of the flag variety $G / B$ . For each minuscule fundamental weight $ϖ$ , we construct an explicit relation in the torus-equivariant quantum $K$ -th…

math.CO2026

Neutral-Fermion constructions of factorial $g p$ -and $g q$ -Functions

Koushik Brahma, Takeshi Ikeda, Shinsuke Iwao +1

We develop neutral-fermionic constructions for the factorial $g p$ -and $g q$ -functions introduced by Nakagawa and Naruse, which are respectively dual to the factorial $GQ$ - and $GP$ -…

math.KT2026

Twisted factorial Grothendieck polynomials and equivariant $K$ -theory of weighted Grassmann orbifolds

Koushik Brahma

In this paper, we provide an explicit description of the Schubert classes in the equivariant $K$ -theory of weighted Grassmann orbifolds. We introduce the `twisted factorial Grothen…

math.AT2024

LS-category and topological complexity of real torus manifolds and Dold manifolds of real torus type

Koushik Brahma, Navnath Daundkar, Soumen Sarkar

The real torus manifolds are a generalization of small covers, and the Dold manifolds of real torus type are a class of non-trivial fibre bundles over the projective product spaces…

math.AT2023

Integral cohomology rings of weighted Grassmann orbifolds and rigidity properties

Koushik Brahma

In this paper, we introduce `Plücker weight vector' and establish the definition of a weighted Grassmann orbifold $Gr_{b} (k, n)$ , corresponding to a Plücker weight vector…

math.AT2023

Integral equivariant $K$ -theory and cobordism ring of simplicial GKM orbifold complexes

Koushik Brahma, Soumen Sarkar

In this paper, we define `simplicial GKM orbifold complexes' and study some of their topological properties. We introduce the concept of filtration of regular graphs and `simplicia…

math.AT2022

Resolution of singularities of toric orbifolds and equivariant cobordism of contact toric manifolds

Koushik Brahma, Soumen Sarkar, Subhankar Sau

Toric orbifolds are a generalization of simplicial projective toric varieties. In this paper, we show that there is a resolution of singularities of a toric orbifold. In a differen…

math.AT2021

Integral generalized equivariant cohomologies of weighted Grassmann orbifolds

Koushik Brahma, Soumen Sarkar

We introduce a new definition of weighted Grassmann orbifolds. We study their several invariant $q$ -cell structures and the orbifold singularities on these $q$ -cells. We discuss wh…

math.AT2019

Blowdown, $k$ -wedge and evenness of quasitoric orbifolds

Koushik Brahma, Soumen Sarkar, Subhankar Sau

In this paper, we introduce polytopal $k$ -wedge construction and blowdown of a simple polytope and inspect the effect on the retraction sequence of a simple polytope due to $k$ -wed…

Minuscule Relations in Quantum K-Theory of Flag Varieties

Neutral-Fermion constructions of factorial gp-and gq-Functions

Twisted factorial Grothendieck polynomials and equivariant K-theory of weighted Grassmann orbifolds

LS-category and topological complexity of real torus manifolds and Dold manifolds of real torus type

Integral cohomology rings of weighted Grassmann orbifolds and rigidity properties

Integral equivariant K-theory and cobordism ring of simplicial GKM orbifold complexes

Resolution of singularities of toric orbifolds and equivariant cobordism of contact toric manifolds

Integral generalized equivariant cohomologies of weighted Grassmann orbifolds

Blowdown, k-wedge and evenness of quasitoric orbifolds

Minuscule Relations in Quantum $K$ -Theory of Flag Varieties

Neutral-Fermion constructions of factorial $g p$ -and $g q$ -Functions

Twisted factorial Grothendieck polynomials and equivariant $K$ -theory of weighted Grassmann orbifolds

Integral equivariant $K$ -theory and cobordism ring of simplicial GKM orbifold complexes

Blowdown, $k$ -wedge and evenness of quasitoric orbifolds