3 papers
math.GR2026
The Fourth Continuous Bounded Cohomology of the Complex Symplectic Group
Sixuan Gu, Yaoyu Cheng, Wei Qi
We prove that $H_{\mathrm{cb}}^4(\Sp(4,\CC);\RR)=0$. Together with Blatz's secondary stability and the rank-one theorem of Bucher--Savini, this gives degree-four vanishing for all…
math.DG2026
A complete classification of left-invariant Einstein metrics on
Sixuan Gu, Wei Qi
We complete the classification of compact simply connected homogeneous Einstein manifolds in dimension six by resolving the remaining cases for left-invariant Einstein metrics on $…
math.RA2026
Transpose Symmetry of Injectivity over Commutative Semirings
Sixuan Gu, Wei Qi, Yaoyu Cheng
Let R be a commutative semiring, not necessarily with a multiplicative identity, and let A be an element of Mn(R). We prove that the map x to Ax on Rn is injective if and only if x…