... Such particles are called ``optically soft'', and the corresponding approximation could be named that of optically soft particles. ... For the theory based on the assumption (1), there are a set of the names: Rayleigh-Gans [ 11 ], Rayleigh-Debye [ 274 , 397 ], Rayleigh-Gans-Born [ 474 ], Rayleigh-Gans-Debye [ 78 , 144 , 409 , 410 ], Rayleigh-Gans-Rokard [ 132 ], Rayleigh-Debye-Gans (RDG) [ 100 , 462 ], Born (or the first Born) [ 56 , 135 ] approximation. ...

... We explore the structures immediately surrounding the intermediate-mass young stellar object R Mon with bispec- trum speckle interferometry, conventional near-infrared imaging and by analyzing optical HST archive data. Our near-infrared speckle images with unprecedented diffraction-limited resolution of 55 mas (44 AU; H -band) and 76 mas (61 AU; K -band) represent the highest resolution R Mon images obtained so far and exhibit previously unseen complex structures. ... The features 1­5 are marked. ...