Niels Feld

collaborators

4 papers

math.KT2026

Finite-coefficient K-theory of henselian valued fields and Gersten injectivity

Niels Feld

Let $W$ be a henselian valuation ring with fraction field $L$ , residue field $k$ , and value group $Γ_{W}$ . Let $N = ℓ^{ν}$ be invertible in $W$ . Choose an ordered $Z / N$ -basis…

math.KT2026

Finite-coefficient Gersten injectivity fails in ramified mixed characteristic

Niels Feld

Let $V$ be a complete discrete valuation ring of mixed characteristic $(0, 3)$ in which $3$ is a uniformizer, and put $A = V [[x, y]] / (3 + x^{2} - y^{3})$ . We construct a nonzero class $a\in K_…

math.AG2026

Homotopy coherent Gysin functoriality

We construct homotopy coherent Gysin pullbacks for weak Borel-Moore theories on smooth schemes, addressing the higher coherence problem for Gysin morphisms associated with closed i…

math.AG2025

Homological Milnor-Witt modules and Chow-Witt groups over general bases

We introduce a general theory of homological Milnor-Witt cycle modules over an excellent base scheme equipped with a dimension function, extending both Rost's cycle modules and Fel…