# Complex integral

1. Dec 11, 2005

### eljose

let be the integral..where $$\zeta(s)$$ is the Riemann zeta function.

$$\int_{c-i\infty}^{c+i\infty}ds\zeta(s)(x^{s}/s)$$

then what would be the result?..there would be two singularities at the points s=0 and s=1 the problem is if there would be any other singularitiy on the integral

2. Dec 11, 2005

### shmoe

This is a straightforward application of Perron's if c>1 and x>0. You surely know where the poles of zeta are by now, no?

3. Dec 12, 2005

### eljose

well i see two poles inside the integral..so i would get the result:

$$A+Bx$$ (poles at s=0 and s=1 with A and B real constants) but it seems a very easy integral, i would expected a sum over the zeros of Riemann Zeta or something similar..uummm..perhaps i have made something wrong.

4. Dec 12, 2005

### shmoe

How did you get this? What contour did you try to apply the residue theorem to? If you want to say something about an unbounded contour you can't apply the residue theorem directly, you have to look at bounded contours and look at limits.

You're seen perron's formula, look at it again closely. There's no way you should expect a sum over the zeros of zeta here.