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I was wishing to start studying by myself the book Functional Analysis by Yosida, does anyone have already used it, is it a good reference?

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You haven't any answers to most of your questions. Please consider going through them and accepting some if you find'em satisfying. – Git Gud Mar 2 '13 at 10:32
Ok, thanks for the tip =D – PtF Mar 2 '13 at 10:34
I meant you haven't accepted any answers to most of your questions. – Git Gud Mar 2 '13 at 10:39
How do I accept them? – PtF Mar 2 '13 at 10:42
No. It is too advanced for beginner – Norbert Mar 2 '13 at 10:59
up vote 5 down vote accepted

Yosida's book is excellent, but certainly not easy reading. It was absolutely cutting edge when it was first published and the style is demanding. I would only recommend it as second or third reading in functional analysis after having achieved a pretty solid background. In addition, some people complain about difficulties understanding the sometimes slightly outdated terminology.

On the positive side, Yosida contains many results and examples that are otherwise hard to find. This is one of the reasons that it still is a widely used reference book which has stood its test of time. Familiarity with it can't hurt...

Since your previous questions indicate that you are relatively new to functional analysis, I would recommend to read something easier going and maybe more modern. You might enjoy Lax's book or Stein and Shakarchi or Reed and Simon. See also

for further recommendations.

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Thanks a lot for the tips =D Indeed I am new to functional analysis, I have just taken a first course in functional analysis using the book "Introductory functional analysis" by Irvin Kreyszig, and I guess it was a nice course, and I want to try something more advanced now, and by what you told me Yosida is gonna be a hard but good choice =D But I'll check those other books too..I didn't know Stein had a book about functional analysis, his exposition's style is great, I guess that must be a nice book.. – PtF Mar 2 '13 at 17:41
Well, you can always give it a try... Only you can decide whether Yosida suits your taste and needs. It's a big step from Kreyszig to Yosida, so don't be discouraged and pick a book of intermediate level if progress is slower than expected. There's a wide variety of good books out there and Yosida surely is among the tougher general texts. // Yes, Stein and Shakarchi's book is a fantastic conclusion of their analysis book series. – Martin Mar 2 '13 at 19:18
I agree =D Thanks for the help again.. – PtF Mar 2 '13 at 19:57

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