576 research outputs found
New Periodic Solutions of Singular Hamiltonian Systems with Fixed Energies
By using the variational minimizing method with a special constraint and the
direct variational minimizing method without constraint, we study second order
Hamiltonian systems with a singular potential and
which may have an unbounded potential well, and
prove the existence of non-trivial periodic solutions with a prescribed energy.
Our results can be regarded as some complements of the well-known Theorems of
Benci-Gluck-Ziller-Hayashi and Ambrosetti-Coti Zelati and so on
A Note on Homoclinic Orbits for Second Order Hamiltonian Systems
In this paper, we study the existence for the homoclinic orbits for the
second order Hamiltonian systems. Under suitable conditions on the potential
, we apply the direct method of variations and the Fourier analysis to prove
the existence of homoclinc orbits
Estimation and Testing for Unit Root Processes with GARCH(1,1) Errors: Theory and Monte Carlo Evidence,
Least squares (LS) and maximum likelihood (ML) estimation are considered for unit root processes with GARCH (1, 1) errors. The asymptotic distributions of LS and ML estimators are derived under the condition alpha + beta
"Estimation and Testing for Unit Root Processes with GARCH (1, 1) Errors: Theory and Monte Carlo Evidence"
Least squares (LS) and maximum likelihood (ML) estimation are con-sidered for unit root processes with GARCH (1, 1) errors. The asymp-totic distributions of LS and ML estimators are derived under the con-dition ƒ¿ + ƒÀ
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