Andrada Pojar

activity

20232026

collaborators

5 papers

math.RA2026

A bound for the nilpotence index associated to $m$ -nil-clean nonderogatory matrices

Andrada Pojar

It is proved that if $F$ is a field of positive characteristic $p,$ and if $m$ and $n$ are positive integers such that $m \geq 2,$ and $4 \leq n \leq p \leq mn - 1,$ for every $n…

math.KT2026

Equivariant Hochschild cohomology of group algebras and relative $Ext$

Andrada Pojar, Constantin-Cosmin Todea

For a finite group $Γ$ , acting on a finite group $G,$ we find necessary conditions for which the first $Γ_{0}$ -equivariant Hochschild cohomology of the group algebra $k G$ is non-triv…

math.RA2025

Nonderogatory matrices as sums of $p$ -potent and nilpotent matrices

Andrada Pojar

We prove that every nonderogatory matrix $A$ over a field of positive odd characteristic $p,$ that is sum of a $p$ -potent matrix and a nilpotent matrix, has a decomposition $A=E+V,…

math.RA2025

Companion matrices as sums of $p$ -potent and nilpotent matrices

Andrada Pojar

We prove that, over a field $F$ of odd characteristic $p$ , a companion matrix $C$ is the sum of $E$ and $N$ , with $E$ $p$ -potent (i.e. $E^{p} = E$ ,) and $N$ nilpotent, if an…

math.RA2023

Companion Weakly Periodic Matrices over Finite and Countable Fields

Peter Danchev, Andrada Pojar

We explore the situation where all companion $n \times n$ matrices over a field $F$ are weakly periodic of index of nilpotence $2$ and prove that this can be happen uniquely when $…

A bound for the nilpotence index associated to m-nil-clean nonderogatory matrices

Equivariant Hochschild cohomology of group algebras and relative Ext

Nonderogatory matrices as sums of p-potent and nilpotent matrices

Companion matrices as sums of p-potent and nilpotent matrices

Companion Weakly Periodic Matrices over Finite and Countable Fields

A bound for the nilpotence index associated to $m$ -nil-clean nonderogatory matrices

Equivariant Hochschild cohomology of group algebras and relative $Ext$

Nonderogatory matrices as sums of $p$ -potent and nilpotent matrices

Companion matrices as sums of $p$ -potent and nilpotent matrices