Moebius Transform Sum: Understanding the mu(x) Function for Prime Numbers

  • Thread starter Thread starter lokofer
  • Start date Start date
  • Tags Tags
    Sum Transform
lokofer
Messages
104
Reaction score
0
let be the sum (over all the divisors d of n):

f(n)= \sum_{d|n} \mu (n/d)g(d) my question is if n=prime then you have only 2 numbers 1 and p that are divisors so you get:

f(p)= \mu (p)g(1) + \mu (1) g(p) is that correct?...now the question is to know what's the value of mu(x) function for x=1 or p. :rolleyes:
 
Physics news on Phys.org
lokofer said:
let be the sum (over all the divisors d of n):

f(n)= \sum_{d|n} \mu (n/d)g(d) my question is if n=prime then you have only 2 numbers 1 and p that are divisors so you get:

f(p)= \mu (p)g(1) + \mu (1) g(p) is that correct?

Correct.

lokofer said:
...now the question is to know what's the value of mu(x) function for x=1 or p. :rolleyes:

Step #1 when trying to learn about mobius inversion and such:

Look at the definition of the mobius function.

Complete this step and \mu(1) and \mu(p) will be apparant.
 
I asked online questions about Proposition 2.1.1: The answer I got is the following: I have some questions about the answer I got. When the person answering says: ##1.## Is the map ##\mathfrak{q}\mapsto \mathfrak{q} A _\mathfrak{p}## from ##A\setminus \mathfrak{p}\to A_\mathfrak{p}##? But I don't understand what the author meant for the rest of the sentence in mathematical notation: ##2.## In the next statement where the author says: How is ##A\to...
The following are taken from the two sources, 1) from this online page and the book An Introduction to Module Theory by: Ibrahim Assem, Flavio U. Coelho. In the Abelian Categories chapter in the module theory text on page 157, right after presenting IV.2.21 Definition, the authors states "Image and coimage may or may not exist, but if they do, then they are unique up to isomorphism (because so are kernels and cokernels). Also in the reference url page above, the authors present two...
##\textbf{Exercise 10}:## I came across the following solution online: Questions: 1. When the author states in "that ring (not sure if he is referring to ##R## or ##R/\mathfrak{p}##, but I am guessing the later) ##x_n x_{n+1}=0## for all odd $n$ and ##x_{n+1}## is invertible, so that ##x_n=0##" 2. How does ##x_nx_{n+1}=0## implies that ##x_{n+1}## is invertible and ##x_n=0##. I mean if the quotient ring ##R/\mathfrak{p}## is an integral domain, and ##x_{n+1}## is invertible then...
Back
Top