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ode matlab problem

shump2 · 2009-04-29 00:54:58

Im trying to solve an ode problem in matlab but i have 2 different derivatives that depend on time for the friedmann fluid equation H = (da./dt) p_m = 0 d(rho_m)./dt + 3*((da./dt)./a)*(rho_m+3*p_m) I can solve the equation if i treat da./dt as a constant leaving it = H(where H = 71)[ But how can i solve it separately ie…

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29-04-2009 1:54am

#1

shump2

Registered Users Posts: 17 ✭

Join Date: June 2008

Posts: 7

Im trying to solve an ode problem in matlab but i have 2 different derivatives that depend on time for the friedmann fluid equation
H = (da./dt)
p_m = 0
d(rho_m)./dt + 3*((da./dt)./a)*(rho_m+3*p_m)

I can solve the equation if i treat da./dt as a constant leaving it = H(where H = 71)[
But how can i solve it separately ie acceleration/time?

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