L. R. Y. Degrassi

activity

20152026

most citedStable invariance of the restricted Lie algebra structure of Hochschild cohomology

6 citations · 6 across the 9 of their papers we have counts for

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8 papers · 1 filter

math.RT2026

Outer derivations on blocks of group algebras

Matthew Antrobus, Benjamin Briggs, Lleonard Rubio y Degrassi

Let $B$ be a block of a finite group algebra $k G$ . Linckelmann has conjectured that if the defect group $P$ of $B$ is nontrivial then $B$ admits a $k$ -linear outer derivation, or i…

math.RT2024

On the first relative Hochschild cohomology

Jonathan Lindell, Lleonard Rubio y Degrassi

In this paper we investigate the Lie algebra structure of the first relative Hochschild cohomology. Let $A, B$ be finite-dimensional basic $k$ -algebras over an algebraically closed…

math.RT2022

On the first Hochschild cohomology of finite dimensional quiver algebras under gluing idempotents

Yuming Liu, Lleonard Rubio y Degrassi, Can Wen

We compare the Lie algebra structures of the first Hochschild cohomology groups of a quiver algebra $A$ and a radical embedding $B$ obtained by gluing two idempotents of $A$ . Under…

math.RT2021

Maximal tori in $H H^{1}$ and the fundamental group

Benjamin Briggs, Lleonard Rubio y Degrassi

We investigate maximal tori in the Hochschild cohomology Lie algebra $H H^{1} (A)$ of a finite dimensional algebra $A$ , and their connection with the fundamental groups associated to p…

math.RT2020★ 6 cited

Stable invariance of the restricted Lie algebra structure of Hochschild cohomology

Benjamin Briggs, Lleonard Rubio y Degrassi

We show that the restricted Lie algebra structure on Hochschild cohomology is invariant under stable equivalences of Morita type between self-injective algebras. Thereby we obtain…

math.RT2019

On the Lie algebra structure of $H H^{1} (A)$ of a finite-dimensional algebra $A$

Markus Linckelmann, Lleonard Rubio y Degrassi

Let $A$ be a split finite-dimensional associative unital algebra over a field. The first main result of this note shows that if the Ext-quiver of $A$ is a simple directed graph, th…

math.RT2016

Block algebras with HH1 a simple Lie algebra

Markus Linckelmann, Lleonard Rubio y Degrassi

We show that if $B$ is a block of a finite group algebra $k G$ over an algebraically closed field $k$ of prime characteristic $p$ such that $\HH^1(B)$ is a simple Lie algebra and su…

math.RT2015

Invariance of the restricted $p$ -power map on integrable derivations under stable equivalences

Lleonard Rubio y Degrassi

We show that the $p$ -power maps in the first Hochschild cohomology space of finite-dimensional selfinjective algebras over a field of prime characteristic $p$ commute with stable e…