Parallel with the theory of general elliptic boundary value problems in smooth
domains, such problems in domains with singularities on the boundary were in-
vestigated. The question on the behaviour of solutions of elliptic boundary value
problems near boundary singularities is of great importance for many applications,
e.g., in aerodynamics, hydrodynamics, fracture machanics. The treatment of ellip-
tic boundary value problems in domains with singularities required a new theory.
On one hand, the methods which were developed for domains with smooth bound-
aries cannot be directly applied to domains with singularities. On the other hand,
many results of the theory for smooth domains are not true if the boundary of the
domain contains singularities.
The pioneering work in the development of a general theory for elliptic bound-
ary value problems in domains with angular and conical points was done by G. I. Es-
kin [65, 66], Ya. B. Lopatinskh , and V. A. Kondrat'ev [98, 99]. The first
two authors investigated boundary value problems in plane domains with angular
points applying the Mellin transformation to an integral equation on the bound-
ary. V. A. Kondrat'ev considered elliptic boundary value problems in domains of
arbitrary dimension with conical points. He applied the Mellin transformation to a
model problem connected with the boundary value problem and proved the Fred-
holm property of the operator of the boundary value problem in weighted and usual
L2 Sobolev spaces of positive integer order. Furthermore, he described the asymp-
totics of the solutions near conical points. Analogous asymptotic representations
for solutions of elliptic boundary value problems in an infinite cylinder were found
in 1963 by S. Agmon and L. Nirenberg .
The gap between V. A. Kondrat'ev's theory and applications was narrowed in
the works of V. G. Maz'ya and B. A. Plamenevskh [142, 143, 144, 147, 149].
These two authors extended the results of V. A. Kondrat'ev to other function spaces
(Lp Sobolev spaces, Holder classes, spaces with inhomogeneous norms), calculated
the coefficients in the asymptotics and described the singularities of the Green
functions. In the monograph of M. Dauge  L2 Sobolev spaces of fractional
order were admitted. Several papers of V. G. Maz'ya, B. A. Plamenevskh [150,
151, 152], V. A. Kozlov, V. G. Maz'ya [111, 112, 113], V. A. Kozlov (e.g.,
[105, 106, 107, 108]), V. A. Kozlov, J. Rofimann [115, 116]), and M. Costabel,
M. Dauge  contain a detailed analysis of the singularities of the solutions to
elliptic boundary value problems near conical points. Other results in this field are
estimates of the Lp-means (V. A. Kozlov, V. G. Maz'ya [109, 110]), the Miranda-
Agmon maximum principle (V. G. Maz'ya, B. A. Plamenevskh , V. G. Maz'ya,
J. Rofimann ), and the construction of stable asymptotics (V. G. Maz'ya,
J. Rofimann , M. Costabel, M. Dauge ).
We also mention the books of P. Grisvard [79, 80], A. Kufner, A.-M. Sandig
, V. G. Maz'ya, S. A. Nazarov, B. A. Plamenevskh , S. A. Nazarov,
B. A. Plamenevskh  and S. Nicaise , where different aspects of the theory
of elliptic boundary value problems in domains with angular and conical points are
A theory of elliptic boundary value problems in domains with cusps or in quasi-
cylindrical domains was established in papers of V. I. Feigin , L. A. Bagirov and
V. I. Feigin , V. G. Maz'ya and B. A. Plamenevskh [139, 147], A. B. Movchan
and S. A. Nazarov [170, 171, 173], J.-L. Steux [239, 240], and M. Dauge .
Elliptic equations on manifolds with cusps were studied further by B. W. Schulze,
B. Sternin, and V. Shatalov [227, 228].