Dark Energy

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These are questions asked by Dark Energy

Hi guys,

I want to solve the matrix equation. suppose we have a matrix A 4*4 which only first array of it (1,1) is equal to n and another matrix such as S which is again 4*4 and generally, we don't know its arrays and we want A and S satisfy the following equation:


how we can find out arrays of S?







I want to find abs(psi)^2 for below psi

psi=int(int(exp(-a*(mu-b)^2)*exp(-c*(V-d)^2)*exp(I*(Q*u-(5/3*Q)*v^(mu/V)-3/16*(v^(4/V)/Q)))*v^((1/2)*(1-V)/V), mu = 0 .. 2), V = -15 .. 15) when mu=0..2 and V=-15..15 for Q:=3, a=10, c=5, b=3 and d=0.

unfortunatelly, I write above psi in maple 18 but it does not work, please tell me how to calculate (abs(psi))^2 for above wave equation (psi).

with the best regard.

Hi guys

I want to solve the following differential equation but I can not. please help me in this way

diff(phi((8*R^(3/2)-W)*sqrt(2)/(24*sqrt(M))), W$2)=lambda*phi((8*R^(3/2)-W)*sqrt(2)/(24*sqrt(M)))


with the best regard

Hello my friends

I want to solve first order non-linear differential equation by maple 2018 but it does not give me the explicit form for a(t) as the function of time t.

this is my equation where z,k,c, and w are non zero constants 

3*a(t)-a(t)^2-3*z*(diff(a(t), t))^2+k*c*a(t)+w/a(t) = 0

please guide me.

with the best regard

Hello guys

I have a simple but crucial question about variation, especially in cosmology and gravity. suppose we have the action such as

S=int(sqrt(-g)*F(R,RµναβRµναβ),d^4x) where g is determinant metric gµν and d^4x is space in 4D and F is an arbitrary function of R (Ricci scalar) and scalar which created by Riemann tensor. How we can define this action in the maple 18 and take variation with respect to the metric.


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