How do I integrate dA(t)A^-1(t)=Bdt?

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In summary, the conversation involves solving two equations that involve matrices and parameters. The first equation can be simplified by multiplying both sides by the left inverse of A(t). The second equation involves finding A(t) and integrating the resulting expression.
  • #1
exmachina
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I have the following two equations

#1

d(A(t))/dt=A(t)B

where A is some matrix that depends on parameter t, and B is another matrix, d is the differential

this can be simplified to by multiplying both sides by the left inverse of A(t),

A^-1(dA(t))=B*t

which allows me to solve A(t) = Ce^(Bt)

#2

d(A(t))/dt=BA(t) note that A and B do not necessarily commute

I'm asked to once again find A(t)

and I get

dA(t)A^-1(t)=Bdt

but how do I integrate this thing?
 
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  • #2
How about this?

[itex]0 = \frac{d}{dt}I = \frac{d}{dt}\left(A(t)A^{-1}(t)\right) = \dot A(t)A^{-1}(t) + A(t)\dot{A^{-1}}(t) \ \ \forall t\in\mathbb{F}[/itex]

Then,

[itex] -A^{-1}(t)\dot A(t)A^{-1}(t) = \dot{A^{-1}(t)}[/itex]

and

[itex] \dot A(t) = -A\dot{A^{-1}}(t)A[/itex]
 

FAQ: How do I integrate dA(t)A^-1(t)=Bdt?

What are non commuting operators?

Non commuting operators are mathematical objects in quantum mechanics that do not commute, meaning that their order of operation matters. This is in contrast to commuting operators, which can be rearranged without changing the outcome.

Why are non commuting operators important in quantum mechanics?

Non commuting operators are important because they represent physical observables in quantum mechanics. The non commutativity of these operators leads to the uncertainty principle, which is a fundamental concept in quantum mechanics.

Can non commuting operators be measured simultaneously?

No, non commuting operators cannot be measured simultaneously. This is because the order of measurement affects the outcome, and the uncertainty principle states that the more precisely one operator is measured, the less precisely the other can be measured.

How do non commuting operators affect the state of a system?

When non commuting operators act on a quantum state, they can change the state and introduce uncertainty in its measurement. The non commutativity of these operators also leads to the concept of superposition, where a system can exist in multiple states simultaneously.

Are there any physical examples of non commuting operators?

Yes, there are many physical examples of non commuting operators. One common example is the position and momentum operators in quantum mechanics. Another example is the spin operators in quantum spin systems, where different components of spin do not commute with each other.

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