带自同构的余弦与正弦加减法则
泛函分析
2023-02-22 v1
摘要
设S为半群。我们的主要结果是刻画下列函数方程的复值解:g(xσ (y)) = g(x)g(y)+f(x)f(y), x,y∈S,f(xσ (y)) = f(x)g(y)+f(y)g(x), x,y∈S,以及f(xσ (y)) = f(x)g(y)-f(y)g(x), x,y∈S,其中σ:S→S为不必对合的自同构。作为推论,我们证明前两个方程与其变体等价。我们也给出若干应用。
引用
@article{arxiv.2302.10263,
title = {Cosine and Sine addition and subtraction law with an automorphism},
author = {Youssef Aserrar and Elhoucien Elqorachi},
journal= {arXiv preprint arXiv:2302.10263},
year = {2023}
}
备注
arXiv admin note: substantial text overlap with arXiv:2210.06181