We consider a parametric nonlinear elliptic problem driven by the sum of a p-Laplacian and of a q-Laplacian (a $(p,q)$-equation) with a singular and $(p-1)$-superlinear reaction and a Robin boundary condition with $(q-1)$-sublinear boundary term $(q<p)$. So, the problem has the combined effects of singular, concave and convex terms. We look for positive solutions and prove a bifurcation-type theorem describing the changes in the set of positive solutions as the parameter varies.

中文翻译：

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具有超线性反应和凹边界条件的奇异 (p, q) 方程

我们考虑一个参数非线性椭圆问题，该问题由p -Laplacian 和q -Laplacian (a$(p,q)$-方程）与单数和$(p-1)$-超线性反应和 Robin 边界条件$(q-1)$-次线性边界项$(q<p)$. 因此，该问题具有奇异项、凹项和凸项的综合影响。我们寻找正解并证明一个分岔型定理，该定理描述了正解集随着参数的变化而发生的变化。