Register to reply

Difficult integral...

by eljose79
Tags: difficult, integral
Share this thread:
eljose79
#1
Aug4-04, 10:03 AM
P: 215
I have problems calculating the integral (here 8 means infinite)

Int(c-i8,c+i8)dsexp(sx)/sR(s) where R(sd) is Riemann,s function i make the change of variable s=c+iu so the new limits are

Int(-8,8)iduexp(cx)exp(iu)/(c+iu)R(c+iu) now what numerical method could i use to calculate it?..thanks.
Phys.Org News Partner Science news on Phys.org
Bees able to spot which flowers offer best rewards before landing
Classic Lewis Carroll character inspires new ecological model
When cooperation counts: Researchers find sperm benefit from grouping together in mice
Feynman
#2
Aug4-04, 10:14 AM
P: 160
what is the analitic expression of R?
eljose79
#3
Aug5-04, 04:59 AM
P: 215
R(s) is Riemann,s zeta function R(s)=1+2^s+3^s+4^s+.............

hope no Feynmann you could give me a hand.

matt grime
#4
Aug5-04, 05:29 AM
Sci Advisor
HW Helper
P: 9,396
Difficult integral...

if only you knew where all the poles were. and if you took a couple of minutes to learn some basic latex your posts would be easier to read. try the thread in general physics
eljose79
#5
Aug6-04, 04:33 AM
P: 215
Latex is hard for me to understand,there are lots opf instruction in fact in the integral...we could do..

Int(-8,8)duexp(iux)/R(c+iu) instead of putting 8 (8=infinite) put N with N big (for example N=10^200000000000) make the change of variable u=Nt then the integral becomes:

Int(-1,1)Ndtexp(iNtx)/R(c+iNt) now the integral (-1,1) can be computed approximately using Gaussian integration.

Yes you could solve it knowing where the poles are but for the function 1/R(s) there are infinite poles so we substitute the problme of calculating an integral to the problem of calculating an infinite series wich is not much better.


Register to reply

Related Discussions
Difficult integral Calculus 19
Difficult integral.... General Math 10
A difficult integral Calculus & Beyond Homework 2
Difficult integral Calculus & Beyond Homework 5
Difficult Integral Introductory Physics Homework 18