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A247226
Decimal expansion of lambda(2), a constant associated with the asymptotic upper tail of the distribution of the first hitting time T_{2,0} for an Ornstein-Uhlenbeck process across the level 2, starting at 0.
0
9, 7, 2, 7, 4, 5, 9, 5, 8, 5, 8, 8, 4, 3, 4, 5, 1, 9, 7, 7, 1, 6, 6, 9, 3, 5, 3, 3, 5, 9, 7, 2, 4, 7, 5, 3, 4, 9, 6, 6, 1, 5, 5, 1, 5, 8, 2, 8, 3, 9, 6, 7, 9, 9, 9, 6, 6, 6, 0, 6, 2, 6, 9, 1, 6, 7, 5, 9, 8, 7, 4, 6, 2, 7, 9, 4, 4, 4, 3, 2, 3, 1, 4, 9, 7, 8, 6, 1, 0, 6, 5, 7, 9, 5, 0, 8, 2, 7, 9, 3, 0, 8, 8, 9
OFFSET
-1,1
LINKS
Steven R. Finch, Ornstein-Uhlenbeck Process, May 15, 2004, p. 7. [Cached copy, with permission of the author]
Eric Weisstein's MathWorld, Parabolic Cylinder Function
FORMULA
lambda(a) = lim_{t->infinity} (1/t)*log(P(T_{a,0}>t)).
lambda(a) is the zero of D_{-lambda}(-a) closest to 0, where D_nu(x) is the parabolic cylinder function or Weber function.
EXAMPLE
-0.09727459585884345197716693533597247534966155...
MATHEMATICA
lambda[a_?NumericQ] := x /. FindRoot[ParabolicCylinderD[-x, -a] == 0, {x, 0}, WorkingPrecision -> 104]; RealDigits[lambda[2]] // First
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
STATUS
approved