Timeline for What are the properties of umbra with moments $\{1,1/2,1/3,1/4,1/5,...\}$?
Current License: CC BY-SA 4.0
17 events
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Dec 10, 2023 at 0:26 | comment | added | Anixx | @SidharthGhoshal well, yes. Moreover, this anti-umbra can be represented as set of integrable functions on interval $(0,1)$, with evaluation operator being $\int_0^1 f(x)dx$ and $\overline{B}=x$, see my recent answer. Unfortunately, for normal, Bernoulli umbra there is no such easy representation. | |
Dec 10, 2023 at 0:13 | comment | added | Sidharth Ghoshal | Ah there probably is some connection with what you’re finding and this idea. $\ln(1+x)$ is the function inverse of $e^x -1$. $\frac{1}{e^x-1}$ has a Laurent series that generates the Bernoulli numbers. $\frac{1}{\ln(1+x)}$ also has a rational Taylor series which encodes some kind of arithmetic information in it. It seems reasonable to wonder if there’s a connection with that and some nice operator of the form $D^{\pm} \Delta^{\pm}$ | |
Dec 9, 2023 at 23:24 | comment | added | Anixx | @SidharthGhoshal $D$ is derivative and $\Delta^{-1}$ is antidifference. | |
Dec 9, 2023 at 23:16 | comment | added | Sidharth Ghoshal | If $\Delta^{-1}$ is a forward difference then what is $D$? I’m trying to interpret the symbol $D\Delta^{-1}$? Is that just a derivative? | |
Dec 9, 2023 at 20:18 | answer | added | Anixx | timeline score: 0 | |
May 27, 2023 at 13:49 | comment | added | Anixx | @TomCopeland ah, inderstood, thanks | |
May 27, 2023 at 13:49 | history | edited | Anixx | CC BY-SA 4.0 |
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May 27, 2023 at 13:45 | comment | added | Tom Copeland | 'It seems' = 'apparently' are usually understood as flagging a conjecture or hypothesis, not a proven statement. I simply note that it is fact, so you can drop the qualification 'it seems'. | |
May 27, 2023 at 13:21 | comment | added | Anixx | @TomCopeland what quaifier do you mean to drop? I did not get it. | |
Feb 3, 2023 at 18:29 | history | edited | Tom Copeland |
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Feb 3, 2023 at 17:09 | comment | added | Tom Copeland | From the sliding average formula in my answer, in my notation, $\psi(\bar{b}.+x) = \psi(\bar{B}.(x)) = \int_x^{x+1} \psi(t) dt = \ln(x)$ (from Wolfram Alpha). | |
Feb 3, 2023 at 16:58 | comment | added | Tom Copeland | In your notation, $\frac{x}{1+\bar{B}x} = x - \bar{B}^1 x^2 + \bar{B}^2 x^3 - \bar{B}^3 x^4 + \cdots$ umbrally evaluated gives $x - \bar{B}_1 x_2 + \bar{B}_2 x^3 - \bar{B}_3 x^4 + \cdots = x - x_2/2 + x^3/3 - x^4 /4+ \cdots = \ln(1+x)$, so you can drop the qualifier 'it seems'. | |
Feb 2, 2023 at 17:05 | history | edited | YCor |
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Feb 2, 2023 at 16:44 | answer | added | Tom Copeland | timeline score: 4 | |
Jan 29, 2023 at 12:33 | comment | added | Anixx | Why is the downvote? | |
Jan 28, 2023 at 15:56 | comment | added | Anixx | Also posted here on Jan, 24: math.stackexchange.com/questions/4624584/… | |
Jan 28, 2023 at 15:55 | history | asked | Anixx | CC BY-SA 4.0 |