Another instructive example in eigenvalue perturbation theory
โ Scribed by M.P. Fry
- Book ID
- 113342044
- Publisher
- Elsevier Science
- Year
- 1979
- Tongue
- English
- Weight
- 126 KB
- Volume
- 86
- Category
- Article
- ISSN
- 0370-2693
No coin nor oath required. For personal study only.
๐ SIMILAR VOLUMES
## Abstract It is shown that there exist domains ฮฉ โ โ^__N__^, which outside of some ball coincide with the strip โ^__N__ โ 1^ ร (0, ฯ) and for which the Dirichlet Laplacian โ ฮ has eigenvalues within the subinterval (1, 4) of the essential spectrum (1, โ).
A Feynman diagram that has three particle intermediate states in all channels is studied. Choosing special values of the masses, in particular taking infrared divergent terms as certain masses go to zero, we explicitly calculate the spectral functions in this limit. They are nonzero in all three reg