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Nathalie Liezel R. Rojas

Publications and source records attributed to Nathalie Liezel R. Rojas.

2 recordsLinked to original sources

Asymptotic evaluation of the Sinc transform of entire exponential type function resulting to exact polynomial asymptotic behavior

We consider the asymptotic evaluation of the integral transform $\int_0^\infty f(x) \, \sin^n(λx)/x^n \,\text{d} x$ of an exponential type function $f(x)$ of type $τ>0$, for large values of the parameter $λ$, where $n$ is a positive integer. We refer to this integral as the Sinc transform. Under the condition that $f(x)$ is even with respect to $x$, we derive a terminating asymptotic expansion of the Sinc transform which behave as a polynomial in positive powers of $λ$ as $λ$ grows large provided that the conditions $λ> τ/2$ for even $n$ and $λ>τ$ for odd n are satisfied.

math.CA↗

Terminating Poincare asymptotic expansion of the Hankel transform of entire exponential type functions

We perform an asymptotic evaluation of the Hankel transform, $\int_0^{\infty}J_ν(λx) f(x)\mathrm{d}x$, for arbitrarily large $λ$ of an entire exponential type function, $f(x)$, of type $τ$ by shifting the contour of integration in the complex plane. Under the situation that $J_ν(λx)f(x)$ has an odd parity with respect to $x$ and the condition that the asymptotic parameter $λ$ is greater than the type $τ$, we obtain an exactly terminating Poincar{é} expansion without any trailing subdominant exponential terms. That is the Hankel transform evaluates exactly into a polynomial in inverse $λ$ as $λ$ approaches infinity.

math.CV↗