We will consider the weakly singular Fredholm integral operator
$T:L^{1}([0,\tau^\star])\rightarrow L^{1}([0,\tau^\star]),\quad
(T\varphi)(\tau)=\frac{\bar\omega}{2} \int_{0}^{\tau^\star}E_{1}(|\tau
-\tau^'|)\varphi(\tau')\,d\tau',$
where $E_{1}$ denotes the first exponential integral function,
$E_{1}(\tau)=\int_{1}^{\infty}\frac{\exp(-\tau\mu)}{\mu}\mu,\quad\tau>0,$
and $\bar\omega$ is a constant. The spectral elements of a matrix operator
representing the discretization of the integral operator $T$ by a projection
method on a subspace of dimension $n$ will be computed. These spectral
elements will be refined iteratively, by a defect correction type formula to
yield an approximation to the spectral elements of $T$.
{{journal.titleEn}} 
DownLoad: