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arXiv · 0907.4436

On linear combinations of two idempotent matrices over an arbitrary field

Clément de Seguins Pazzis
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Abstract

Given an arbitrary field K and non-zero scalars a and b, we give necessary and sufficient conditions for a matrix A in M_n(K) to be a linear combination of two idempotents with coefficients a and b. This extends results previously obtained by Hartwig and Putcha in two ways: the field K considered here is arbitrary (possibly of characteristic 2), and the case a is different from b and -b is taken into account.

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Clément de Seguins Pazzis. 2009-07-25. On linear combinations of two idempotent matrices over an arbitrary field. https://doi.org/10.1016/j.laa.2010.03.023

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