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4 votes
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86 views

Characterizing the separability of the Gelfand space of a semisimple commutative Banach algebra

Problem. Is the separability of the Gelfand space of a semi-simple commutative Banach algebra $A$ equivalent to the existence of a countable family $\{\varphi_n\}_{n\in\omega}$ of multiplicative ...
Lviv Scottish Book's user avatar
3 votes
0 answers
160 views

Non-emptiness of spectrum $\sigma(a)$ in non-Archimedean Banach algebras

I'm trying to determine whether or not the standard proof that the spectrum of a point in a unital Banach algebra is non-empty can be adapted to prove the same thing over certain non-Archimedean ...
Very Forgetful Functor's user avatar
2 votes
0 answers
176 views

Banach Algebras and the peripheral spectrum

Here is a little theorem that I'm trying to prove. I haven't seen it in literature before, but I think the applications will be quite useful, particularly in the context of Banach algebras. Denote ...
ChantelD's user avatar
1 vote
0 answers
80 views

What is the character space of $\mathcal P(K)$?

Let $K$ be a compact subset of $\Bbb C$. Let $\mathcal P(K)$ be the closed algebra generated by the complex polynomials on $K$. What is the character space $\Phi_{\mathcal P(K)}$ of $\mathcal P(K)$?...
BigbearZzz's user avatar
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0 votes
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Regarding significance of spectral variation under algebraic operations

I have been reading the paper Determining elements in $C^∗$-algebras through spectral properties. The paper discusses about what would be the relation be between two elements $a$ and $b$ of a Banach ...
user332905's user avatar