Kelvin transform for Grushin operators and critical semilinear equations
Kelvin transform for Grushin operators and critical semilinear equations
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DOI:
10.1215/s0012-7094-05-13115-5
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发表时间:
2006-01
影响因子:
2.5
通讯作者:
R. Monti;Daniele Morbidelli
中科院分区:
文献类型:
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作者:
R. Monti;Daniele Morbidelli
We study positive entire solutions u = u(x, y) of the critical equation xu+ (α + 1)2|x|2α yu = −u(Q+2)/(Q−2) in R = R × R, (1) where (x, y) ∈ Rm×Rk , α > 0, and Q = m+ k(α+1). In the first part of the article, exploiting the invariance of the equation with respect to a suitable conformal inversion, we prove a “spherical symmetry” result for solutions. In the second part, we show how to reduce the dimension of the problem using a hyperbolic symmetry argument. Given any positive solution u of (1), after a suitable scaling and a translation in the variable y, the function v(x) = u(x, 0) satisfies the equation divx(p∇xv) − qv = −pv(Q+2)/(Q−2), |x| < 1, (2) with a mixed boundary condition. Here, p and q are appropriate radial functions. In the last part, we prove that if m = k = 1, the solution of (2) is unique and that for m ≥ 3 and k = 1, problem (2) has a unique solution in the class of x-radial functions.