hsfzLZH1's Homepage
2026
- Why a proper algebraic intersection should have positive multiplicity
- Flat local maps cannot lower multiplicity
- A three-dimensional singularity that no finite module can make Cohen–Macaulay
- One finite algebra with arbitrarily long terminating resolutions
- Zero divisors without finite-order group elements
- A one-sided inverse that cannot be reversed in a group algebra
- Vanishing self-extensions need not make a module projective
- The largest relation counts come from a lex-plus-powers ideal
- Two algebraic generators can produce an infinite-dimensional division ring
- Counting modular representations from local weights