Unknown symbol that looks like Q

[woundedtiger4]

I have checked it is not Greek, looks like Q , am I right?

Thanks in advance

 

[fzero]

Yes, it's a calligraphic Q, $\mathcal{Q}$.

 

[woundedtiger4]

Yes, it's a calligraphic Q, $\mathcal{Q}$.

Thank you sir