On the integrability of functions defined by trigonometrical series

1956 ◽  
Vol 66 (1) ◽  
pp. 9-12 ◽  
Author(s):  
Chen Yung-Ming
1938 ◽  
Vol s2-43 (1) ◽  
pp. 366-375 ◽  
Author(s):  
W. M. Shepherd

1954 ◽  
Vol 5 (3) ◽  
pp. 296-301 ◽  
Author(s):  
Shin-ichi Izumi

1999 ◽  
Vol 172 ◽  
pp. 243-248
Author(s):  
S. Ferraz-Mello

AbstractThe word “average” and its variations became popular in the sixties and implicitly carried the idea that “averaging” methods lead to “average” Hamiltonians. However, given the Hamiltonian H = H0(J) + ϵR(θ,J),(ϵ ≪ 1), the problem of transforming it into a new Hamiltonian H* (J*) (dependent only on the new actions J*), through a canonical transformation given by zero-average trigonometrical series has no general solution at orders higher than the first.


1955 ◽  
Vol 31 (5) ◽  
pp. 257-260
Author(s):  
Shin-ichi Izumi

Author(s):  
J. Cossar

SynopsisThe series considered are of the form , where Σ | cn |2 is convergent and the real numbers λn (the exponents) are distinct. It is known that if the exponents are integers, the series is the Fourier series of a periodic function of locally integrable square (the Riesz-Fischer theorem); and more generally that if the exponents are not necessarily integers but are such that the difference between any pair exceeds a fixed positive number, the series is the Fourier series of a function of the Stepanov class, S2, of almost periodic functions.We consider in this paper cases where the exponents are subject to less stringent conditions (depending on the coefficients cn). Some of the theorems included here are known but had been proved by other methods. A fuller account of the contents of the paper is given in Sections 1-5.


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