Regularization of $\lim_{n\to\infty}n^s$ using Zeta Function

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I will be considering the Riemann Zeta Function to assign values to some limits.

Values of $\zeta(s)$ at negative integer arguments are known.

For example,

$$\zeta(0)=-\frac{1}{2}\stackrel{\Re}{=}\sum_{n=1}^{\infty}1$$ $$\zeta(-1)=-\frac{1}{12}\stackrel{\Re}{=}\sum_{n=1}^{\infty}n$$

This got me wondering what would happen if we take the Partial Sums first and then put the limit as follows:

(I will be omitting the $\Re$ above the equality sign but assume we are only assigning values here)

$$-\frac{1}{2}=\lim_{n\to\infty}n$$

$$-\frac{1}{12}=\lim_{n\to\infty}\frac{n(n+1)}{2}$$

Now we can eliminate $n$ from the Second Limit and find the value for $n^2$.

$$\lim_{n\to\infty}n^2=\frac{1}{3}$$

I tried this process further and got the following examples,

$$\lim_{n\to\infty}n^3=-\frac{1}{4}$$

$$\lim_{n\to\infty}n^4=\frac{1}{5}$$

So it seems that,

$$\lim_{n\to\infty}n^{s}=\frac{(-1)^s}{1+s}$$

Can we prove this regularization?

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I was able to solve it by reducing it to Bernoulli Numbers:

It is known that,

$$\sum_{k=1}^nk^c=\frac{1}{1+c}\sum_{k=0}^c\binom{c+1}{k}B_kn^{c+1-k}$$

So if we take the limit as $n\to \infty$ and assign the values.

$$\zeta(-c)=\frac{1}{1+c}\sum_{k=0}^c\binom{c+1}{k}\frac{B_k(-1)^{c+1-k}}{1+c+1-k}$$

But,

$$\zeta(-c)=-\frac{B_{1+c}}{1+c}$$

This gives us.

$$-B_{n}=(-1)^n\sum_{k=0}^{n-1}(-1)^{k}\binom{n}{k}\frac{B_k}{n+1-k}$$

Which is a recurrence for Bernoulli Numbers, mentioned on Wikipedia.