What are coherent sources? How are they produce?
Answers
Answer:
Two sources are said to be coherent when the waves emitted from them have the same frequency and constant phase difference. Interference from such waves happen all the time, the randomly phased light waves constantly produce bright and dark fringes at every point.
Answer:
In proof theory, a coherent space is a concept introduced in the semantic study of linear logic.
Let a set C be given. Two subsets S,T ⊆ C are said to be orthogonal, written S ⊥ T, if S ∩ T is ∅ or a singleton. The dual of a family F ⊆ ℘(C) is the family F ⊥ of all subsets S ⊆ C orthogonal to every member of F, i.e., such that S ⊥ T for all T ∈ F. A coherent space F over C is a family C-sets for which F = (F ⊥) ⊥.
In Proofs and Types coherent spaces are called coherence spaces. A footnote explains that although in the French original they were espaces cohérents, the coherence space translation was used because spectral spaces are sometimes called coherent spaces