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exact def of xi_r and xi_h

Posted: Fri Jan 20, 2017 12:54 pm
by jingluan
Are the xi_r and xi_h in the output mode file consistent with the following formula please? I define er, etheta, and ephi as the normal vectors along r, theta, and phi directions in a spherical coordiantes, and Y_{lm} is the normalized spherical harmonic.

xi (vector) = xi_r *Y_{lm}*er + xi_h *({\partial Y_{lm} \over \partial theta}*etheta + 1/sin(theta)*{\partial Y_{lm} \over \partial\phi}*ephi

Although this is the conventional definition, I still like to make it sure, many thanks :-D

Sincerely,
Jing

Re: exact def of xi_r and xi_h

Posted: Fri Jan 20, 2017 12:58 pm
by rhtownsend
jingluan wrote:Are the xi_r and xi_h in the output mode file consistent with the following formula please? I define er, etheta, and ephi as the normal vectors along r, theta, and phi directions in a spherical coordiantes, and Y_{lm} is the normalized spherical harmonic.

xi (vector) = xi_r *Y_{lm}*er + xi_h *({\partial Y_{lm} \over \partial theta}*etheta + 1/sin(theta)*{\partial Y_{lm} \over \partial\phi}*ephi

Although this is the conventional definition, I still like to make it sure, many thanks :-D

Sincerely,
Jing
Hi Jing --

Thanks for your post. The answer is 'yes', with the following two provisos:

1) You appear to be missing a close parenthesis ')' at the end of your expression. The xi_h term multiplies the etheta *and* ephi components

2) xi_r and xi_h have units of the stellar radius R*, meaning that xi (vector) will have the same units.

cheers,

Rich

Re: exact def of xi_r and xi_h

Posted: Tue Jan 16, 2018 5:23 am
by Gabriel
Got it! Thanks for the clarification.