Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Physics, 2005.Includes bibliographical references (leaf 35).Oscillons are localized solutions of nonlinear field theories that oscillate without dissipation. We have numerically found a family of very long-lived oscillons the spherical ansatz of the SU(2) gauged Higgs model -the standard model of the weak interactions without electromagnetism and fermions. In this thesis, we study the stability of these objects. We do this by adding a massless mode to the model and coupling it to the oscillating fields contained in the Higgs doublet. Such a mode is expected to provide a decaying mechanism for the oscillons. However, numerical investigation shows that our oscillons do not decay if the massless mode is sufficiently weakly coupled and suggests that our oscillons are stable long-lived solutions that could substantially influence the dynamics of this theory.by Ruza Markov.S.B
