7 papers
Arbitrary Stage Spectra for Raikov Remainders Along Quotient Towers
Xing-Yu Hu
Let be an ordinal and let be a continuous increasing tower of closed normal subgroups of a Hausdorff topological group , with . Write for th…
Bistationary Traces, Wide Levels, and Branch-Cover Rigidity for an Unrestricted Typed Variant of the Hayut-Magidor Forcing
Xing-Yu Hu
For every uncountable regular cardinal , is an explicitly typed four-coordinate forcing motivated by the ladder-system construction of Hayut and Magidor. T…
Idempotent-free non-solvable evolution algebras over
Xing-Yu Hu, Ran Wen
A recent conjecture states that a finite-dimensional complex evolution algebra is solvable if and only if it has no non-zero idempotents. We exhibit a three-dimensional counterexam…
Dense-Kernel and Closed-Core Reductions in the D-space Problem for Charming Spaces
Xing-Yu Hu, Ze-Qi Yin
Let X be a charming space with a Lindelof Sigma kernel Y, and let B be the closure of Y in X. We show that the question whether every charming space is a D-space can be reduced fir…
Dense-set dependence in the Katětov order for uncountable coordinate ideals
Xing-Yu Hu, Zhang-Yi Luo
For each countable ordinal , Filipów, Kowalczuk and Kwela introduced an ideal on the countable compact ordinal space . Kowalczuk later proved that…
Carrier ideals, tail obstructions, and remainder traces for ladder-system spaces
Xing-Yu Hu
For a ladder-system space with carrier , the finite-label uniformization property characterizes countable metacompactness, and countable metaco…
Raikov Remainders of Quotients by Raikov-Complete Almost Metrizable Normal Subgroups
Xing-Yu Hu
Let \(N\) be a closed normal subgroup of a topological group \(G\), and let \(\widehat q:ρG\toρ(G/N)\) extend the quotient homomorphism. We prove that \(r_ρ(G/N)=\widehat q\bigl(r_…