2008 ◽  
Vol 3 (2) ◽  
pp. 453-469 ◽  
Author(s):  
John R. King ◽  
Scott W. McCue

1993 ◽  
Vol 24 (9) ◽  
pp. 701-705
Author(s):  
F Guinea ◽  
O Pla ◽  
E Louis

2005 ◽  
Vol 5 (1) ◽  
pp. 19-48 ◽  
Author(s):  
Dmitry Khavinson ◽  
Alexander Yu. Solynin ◽  
Dimiter Vassilev

2021 ◽  
Vol 8 (4) ◽  
Author(s):  
Mikko Salo ◽  
Henrik Shahgholian

AbstractWe study a question arising in inverse scattering theory: given a penetrable obstacle, does there exist an incident wave that does not scatter? We show that every penetrable obstacle with real-analytic boundary admits such an incident wave. At zero frequency, we use quadrature domains to show that there are also obstacles with inward cusps having this property. In the converse direction, under a nonvanishing condition for the incident wave, we show that there is a dichotomy for boundary points of any penetrable obstacle having this property: either the boundary is regular, or the complement of the obstacle has to be very thin near the point. These facts are proved by invoking results from the theory of free boundary problems.


Fractals ◽  
1999 ◽  
Vol 07 (01) ◽  
pp. 33-39 ◽  
Author(s):  
VINCENT FLEURY ◽  
LAURENT SCHWARTZ

A model is proposed by which the formation of the vascular network in animals proceeds via progressive penetration of the vessel ramification into a capillary mesh, by means of a laplacian growth mechanism of hydrodynamical origin. In this model, the growth of both arteries and veins follows the directions of high shear stress provoked by the blood flow on the endothelial wall of a pre-existing capillary mesh. This process is shown to be identical to the phenomenon of dendritic growth, which is responsible for the formation of such well-known patterns as dendritic crystals, lightning sparks or branching aggregates of bacteria. A number of straightforward consequences of potentially important medical and physiological interests are deduced. These include the natural and spontaneous organization of the arterial and venal trees, the spontaneous and unavoidable tropism of arteries towards veins and vice-versa, the hierarchical character of the vessels and the possibility of computerized prediction of the vascular pattern from the shape of the capillary bed.


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