text: A field whose amplitude is given by a Bessel function of the first kind would anomalously not demonstratethis effect.
full_question: A field whose amplitude is given by a Bessel function of the first kind would anomalously not demonstratethis effect. An equation for this phenomenon has a leading term of i over lambda times the surface integral ofthe average of the cosine of two angles, and is derived using two of Kirchoff's boundary conditions. Under theparaxial approximation, this phenomenon is governed by an equation with a sinc squared term applied to avariable symbolized beta. The equation 2 d, sine theta, equals n lambda is used to describe how it distinguishescrystal structures. This phenomenon and interference create alternating light and dark bands on the farscreen in Young's double-slit experiment. For 10 points, name this process in which light bends around anobstacle. 
first_sentence: A field whose amplitude is given by a Bessel function of the first kind would anomalously not demonstratethis effect.
raw_answer: diffraction [prompt on interference] 