How to force Mathematica (NIntegrate) to output real values

Questions
,
1

Here’s the issue. I have a function that yields a value for NIntegrate of a Real and an Imaginary term of comperable sizes. If Mathematica treats all values internally as complex values, then I need to limit the branch used in the integration to only the one that yields a real value and no imaginary component.

The integrand is alway greater than zero, so there is no obvious pole, yet the complex output persists. I am not sure what assumptions or requirements will force the answer to always be real.

Thanks for any explanation of what is going on and how to get the real value I am looking for.

Luther

2

You say that the real and imaginary parts are of comparable size. Are they both close to 0 in magnitude?
In that case the integral is probably 0.

3

That was my thought, also, but it is more complicated that that. The actual value should be small but the integrand is definitely not zero anywhere.

I will force the size of the integrand to be both larger and farther from zero, which exceeds the scenario I am interested in but will help nail down the origin of the issue.