Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Self-similar relaxation dynamics of a fluid wedge in a Hele-Shaw cell   Let the interface between two immiscible fluids in a Hele-Shaw cell have, at
t=0, a wedge shape. As a wedge is scale-free, the fluid relaxation dynamics are
self-similar. We find the dynamic exponent of this self-similar flow and show
that the interface shape is given by the solution of an unusual inverse problem
of potential theory. We solve this inverse problem analytically for an almost
flat wedge, and numerically otherwise. The wedge solution is useful for
analysis of pinch-off singularities.

27
The categories of this paper are: comp-gas
31
The categories of this paper are: ao-sci
14
The categories of this paper are: math-ph
8
The categories of this paper are: hep-ex
26
The categories of this paper are: bayes-an
30
The categories of this paper are: q-alg
0
The categories of this paper are: hep-ph
15
The categories of this paper are: nucl-ex
22
The categories of this paper are: chao-dyn
18
The categories of this paper are: econ
32
The categories of this paper are: atom-ph
12
The categories of this paper are: nucl-th
37
The categories of this paper are: supr-con
23
The categories of this paper are: solv-int
21
The categories of this paper are: adap-org
11
The categories of this paper are: hep-lat