Chi-Ming Chang

collaborators

5 papers

math.RT2026

Super-Chevalley Restriction and Relative Lie Algebra Cohomology over the 2|3 Algebra

Chi-Ming Chang

Let $A := C [z_{+}, z_{-}] \otimes I^ (I^¸_{1}, I^¸_{2}, I^¸_{3})$ , with $z_{\pm}$ even and $I^¸_{1}, I^¸_{2}, I^¸_{3}$ odd. For a reductive Lie algebra $g$ , let $\mathfrak g[A]:=\mathfrak g\otim…

hep-th2026

Classification of 2D Fermionic Systems with a $Z_{2}$ Flavor Symmetry

Chi-Ming Chang, Jin Chen, Fengjun Xu

We classify superfusion categories describing two-dimensional fermionic systems equipped with the universal fermion-parity symmetry, implemented by a topological defect line (TDL)…

hep-th2026

Fortuity in the D1-D5 system

Chi-Ming Chang, Ying-Hsuan Lin, Haoyu Zhang

We reformulate the lifting problem in the D1-D5 CFT as a supercharge cohomology problem, and enumerate BPS states according to the fortuitous/monotone classification. Working in th…

hep-th2025

Fortuity and R-charge concentration in the D1-D5 CFT

Chi-Ming Chang, Haoyu Zhang

We investigate finite- $N$ BPS cohomology in the D1--D5 CFT, focusing on the sector of fortuitous classes. Analyzing the supercharge cochain complexes in the $N = 2$ and $N = 3$ theorie…

hep-th2025

Violation of S-duality in classical $Q$ -cohomology

Chi-Ming Chang, Ying-Hsuan Lin

We study the cohomology of a chiral supercharge $Q$ in the $N = 4$ super-Yang-Mills (SYM) theory at tree level. The cohomology classes correspond one-to-one to the $\frac1{…

Super-Chevalley Restriction and Relative Lie Algebra Cohomology over the 2|3 Algebra

Classification of 2D Fermionic Systems with a Z2​ Flavor Symmetry

Fortuity in the D1-D5 system

Fortuity and R-charge concentration in the D1-D5 CFT

Violation of S-duality in classical Q-cohomology

Classification of 2D Fermionic Systems with a $Z_{2}$ Flavor Symmetry

Violation of S-duality in classical $Q$ -cohomology