We consider the Laplacian on a class of smooth domains pport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0021782416300058&_mathId=si1.gif&_user=111111111&_pii=S0021782416300058&_rdoc=1&_issn=00217824&md5=ac5882de620b3391149f2b7c9097b18e" title="Click to view the MathML source">Ω⊂Rν, pport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0021782416300058&_mathId=si2.gif&_user=111111111&_pii=S0021782416300058&_rdoc=1&_issn=00217824&md5=9aed457c49913b77b80deae5891d5b06" title="Click to view the MathML source">ν≥2, with attractive Robin boundary conditions:
where n is the outer unit normal, and study the asymptotics of its eigenvalues as well as some other spectral properties for α tending to +∞. We work with both compact domains and non-compact ones with a suitable behavior at infinity. For domains with compact pport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0021782416300058&_mathId=si5.gif&_user=111111111&_pii=S0021782416300058&_rdoc=1&_issn=00217824&md5=3fd7f5e24fa3df83d9db14804e42283a" title="Click to view the MathML source">C2 boundaries we show that, for each fixed j,
where pport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0021782416300058&_mathId=si7.gif&_user=111111111&_pii=S0021782416300058&_rdoc=1&_issn=00217824&md5=58d1bef3381dc5ce08e7b5c033563a96" title="Click to view the MathML source">μj(α) is the j th eigenvalue of the operator pport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0021782416300058&_mathId=si8.gif&_user=111111111&_pii=S0021782416300058&_rdoc=1&_issn=00217824&md5=c92562f8d4adb4805c6e48d048b531cd" title="Click to view the MathML source">−ΔS−(ν−1)αH with pport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0021782416300058&_mathId=si9.gif&_user=111111111&_pii=S0021782416300058&_rdoc=1&_issn=00217824&md5=e283f52bd06b8bfc83b51683c2ce6e76" title="Click to view the MathML source">(−ΔS) and H being respectively the positive Laplace–Beltrami operator and the mean curvature on ∂Ω. Analogous results are obtained for a class of domains with non-compact boundaries. In particular, we discuss the existence of eigenvalues for non-compact domains and the existence of spectral gaps for periodic domains. We also show that the remainder estimate can be improved under stronger regularity assumptions.
The effective Hamiltonian pport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0021782416300058&_mathId=si8.gif&_user=111111111&_pii=S0021782416300058&_rdoc=1&_issn=00217824&md5=c92562f8d4adb4805c6e48d048b531cd" title="Click to view the MathML source">−ΔS−(ν−1)αH enters the framework of semi-classical Schrödinger operators on manifolds, and we provide the asymptotics of its eigenvalues for large α under various geometric assumptions. In particular, we describe several cases for which our asymptotics provides gaps between the eigenvalues of for large α.