DIfference of error functions with complex arguments

*To*: mathgroup at smc.vnet.net*Subject*: [mg77145] DIfference of error functions with complex arguments*From*: Ale <theopps75 at yahoo.it>*Date*: Tue, 5 Jun 2007 06:26:58 -0400 (EDT)

Hi... I am studing the harmonic responce of a photophysical system. After a convolutio, part the solution contains: \!\(Erf[\(\((\(-1\))\)\^\(1/4\)\ \((a + 2\ \@t\ \((1 - \[ImaginaryI]\ =CF=86)\))\)\ \)\/\(2\ \@\(\[ImaginaryI] + =CF=86\)\)] - Erf[\(\((\(-1\))\)\^\(1/4\)\ a\) \/\(2\ \ \@\(\[ImaginaryI] + =CF=86\)\)]\) That is the difference between two error functions of complex argument. Knowing that the following assumptions can be used: Assumptions -> {a > 0, =CF=86 > 0, t > 0, a =CF=86 t =E2=88=88 Reals} Can I somehow obtain this part of equation in the form Ro Exp [-i Phi] ? More in general, if one have Erf[x]+Erf[y], with x and y complex numbers, is it possible to express analytically the module and argument of the sum? Thanks Alessandro