Speaker
Dr
Noburo Shiba
Description
We consider the (Renyi) mutual information, I^(n) (A,B)=S^(n)_A +S^(n)_B −S^(n)_ A∪B , of distant compact spatial regions A and B in the vacuum state of a free scalar field. The distance r between A and B is much greater than their sizes R A,B . It is known that I^(n)_(A,B)∼C^(n)_AB ⟨0|ϕ(r)ϕ(0)|0⟩^2 . We obtain the direct expression of C^(n)_AB for arbitrary regions A and B. We perform the analytical continuation of n and obtain the mutual information. The direct expression is useful for the numerical computation. By using the direct expression, we can compute directly I(A,B) without computing S_A ,S_B and S_A∪B respectively, so it reduces significantly the amount of computation.
