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The second-order
ordinary differential equation
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(1)
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This differential equation has an irregular singularity at . It can be
solved using the series method
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(2)
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![(2a_2+lambdaa_0)+sum_(n=1)^infty[(n+2)(n+1)a_(n+2)-2na_n+lambdaa_n]x^n=0.](/images/equations/HermiteDifferentialEquation/NumberedEquation3.gif) |
(3)
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Therefore,
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(4)
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and
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(5)
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for , 2, .... Since (4)
is just a special case of (5),
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(6)
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for , 1, ....
The linearly independent solutions are then
These can be done in closed form as
where is a confluent hypergeometric function of the first kind and is a Hermite polynomial. In particular, for , 2, 4,
..., the solutions can be written
where is the erfi
function.
If , then Hermite's differential
equation becomes
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(16)
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which is of the form
and so has solution
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