5,080 research outputs found
Spectral bounds for the cutoff Coulomb potential
The method of potential envelopes is used to analyse the bound-state spectrum
of the Schroedinger Hamiltonian H = -Delta -v/(r+b), where v and b are
positive. We established simple formulas yielding upper and lower energy bounds
for all the energy eigenvalues.Comment: 11 pages, 2 figure
Dispersal of \u3ci\u3eFenusa Dohrnii\u3c/i\u3e (Hymenoptera: Tenthredinidae) From an \u3ci\u3eAlnus\u3c/i\u3e Short-Rotation Forest Plantation
The European alder leafminer, Fenusa dohrnii, is a defoliating insect pest of Alnus in short-rotation forest plantations. A 2-year study was performed to quantify movement from infested stands to uninfested areas. Sticky traps and potted monitor trees were installed at different locations within and at various distances from (0,5, 10, and 20 m) an infested stand to measure adult flight and oviposition activity, respectively. Trap catch and oviposition activity fell off sharply with distance, few insects being trapped or eggs laid at distances of 5 m or greater from the infestation
Eigenvalue bounds for a class of singular potentials in N dimensions
The eigenvalue bounds obtained earlier [J. Phys. A: Math. Gen. 31 (1998) 963]
for smooth transformations of the form V(x) = g(x^2) + f(1/x^2) are extended to
N-dimensions. In particular a simple formula is derived which bounds the
eigenvalues for the spiked harmonic oscillator potential V(x) = x^2 +
lambda/x^alpha, alpha > 0, lambda > 0, and is valid for all discrete
eigenvalues, arbitrary angular momentum ell, and spatial dimension N.Comment: 10 pages (plain tex with 2 ps figures). J.Phys.A:Math.Gen.(In Press
Gravitating semirelativistic N-boson systems
Analytic energy bounds for N-boson systems governed by semirelativistic
Hamiltonians of the form H=\sum_{i=1}^N(p_i^2 + m^2)^{1/2} - sum_{1=i<j}^N
v/r_{ij}, with v>0, are derived by use of Jacobi relative coordinates. For
gravity v=c/N, these bounds are substantially tighter than earlier bounds and
they are shown to coincide with known results in the nonrelativistic limit.Comment: 7 pages, 2 figures It is now proved that the reduced Hamiltonian is
bounded below by the simple N/2 Hamiltonia
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