Niels Feld

activity

20182026

most citedMW-homotopy sheaves and Morel generalized transfers

4 citations · 9 across the 11 of their papers we have counts for

collaborators

12 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

Frédéric Déglise, Niels Feld, Fangzhou Jin

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

Frédéric Déglise, Niels Feld, Fangzhou Jin

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…

math.AG2023

Moving lemmas and the homotopy coniveau tower

Frédéric Déglise, Niels Feld, Fangzhou Jin

In this note we study the functoriality of the coniveau filtration in motivic homotopy theory via a moving lemma over a base scheme, extending previous works of Levine and Bachmann…

math.AG2022

Perverse homotopy heart and MW-modules

Frédéric Déglise, Niels Feld, Fangzhou Jin

We compute the perverse delta-homotopy heart of the motivic stable homotopy category over a base scheme with a dimension function delta, rationally or after inverting the exponenti…

math.AG2022★ 1 cited

Birational invariance of the Chow-Witt group of zero-cycles

Niels Feld

We prove that the Chow-Witt group of zero-cycles is a birational invariant of smooth proper schemes over a base field.

math.AG2021

A vanishing theorem for quadratic intersection multiplicities

Niels Feld

We study intersection theoretic problems in the setting of Chow-Witt groups with coefficients in a fixed Milnor-Witt cycle algebra over a perfect field. We prove that the product m…

math.AG2020★ 2 cited

Transfers on Milnor-Witt K-theory

Niels Feld

We give a new proof of the fact that Milnor-Witt K-theory has geometric transfers. The proof yields to a simplification of Morel's conjecture about transfers on contracted homotopy…

math.AG2020★ 4 cited

MW-homotopy sheaves and Morel generalized transfers

Niels Feld

We explore a conjecture of Morel about the Bass-Tate transfers defined on the contraction of a homotopy sheaf and prove that the conjecture is true with rational coefficients. More…

math.AG2019★ 2 cited

Morel Homotopy Modules and Milnor-Witt Cycle Modules

Niels Feld

We study the cohomology theory and the canonical Milnor-Witt cycle module associated to a motivic spectrum. We prove that the heart of Morel-Voevodsky stable homotopy category over…

math.AG2018

Milnor-Witt Cycle Modules

Niels Feld

We generalize Rost's theory of cycle modules using Milnor-Witt K-theory instead of the classical Milnor K-theory. We obtain a (quadratic) setting to study general cycle complexes a…