  A set of theoretical results [1-10] is reviewed, which concern calculations
of energy spectra, density of energy levels, spin polarization, transport and
optical properties (infrared absorption, luminescence) of semiconductor quantum
dots and atomic traps. The studied systems contain a number of particles
between 4 and 400, thus the calculation of their physical properties is a hard
task. The analogy between these systems and the atomic nuclei is stressed and
used throughout the paper. Common Nuclear Physics methods like Hartree-Fock and
RPA schemes for finite systems, the BCS approach and the Lipkin-Nogami
projection, and the Bethe-Goldstone equation were adapted to the present
context. On the other hand, the Schrodinger equation was solved in basis with
up to 40,000 functions by means of the Lanczos algorithm, and other methods
like variational Monte Carlo estimations and two-point Pade approximants were
also applied. Lastly, a stochastic projection of the BCS wave function was
implemented.
