2 citations · 4 across the 5 of their papers we have counts for
6 papers
Flat maps to and from Noetherian rings
Justin Chen
We investigate flat maps where the source or target is a Noetherian ring, giving necessary and/or sufficient conditions on a ring for such maps to exist. Along the way, we develop…
Infinite prime avoidance
Justin Chen
We investigate prime avoidance for an arbitrary set of prime ideals in a commutative ring. Various necessary and/or sufficient conditions for prime avoidance are given, which yield…
Surjections of unit groups and semi-inverses
Justin Chen
Given a surjective ring homomorphism, we study when the induced group homomorphism on unit groups is surjective. To this end, we introduce notions of generalized inverses and units…
Mono: an algebraic study of torus closures
Justin Chen
Given an ideal I in a polynomial ring, we consider the largest monomial subideal contained in I, denoted mono(I). We study mono as an interesting operation in its own right, guided…
Closed points on schemes
Justin Chen
This brief note gives a survey on results relating to existence of closed points on schemes, including an elementary topological characterization of the schemes with (at least one)…
Invertible sums of matrices
Justin Chen
We give an elementary proof of a Caratheodory-type result on the invertibility of a sum of matrices, due first to Facchini and Barioli. The proof yields a polynomial identity, expr…