Is T = T^-1 in Lorentz Transformations for 4 Vectors?

AI Thread Summary
The discussion centers on whether the Lorentz transformation matrix T satisfies the condition T^v_u = T^u_v^-1 or if T equals its own inverse. Participants clarify that T being equal to its inverse would imply T^T = T^-1, which is not generally true for Lorentz transformations of 4-vectors. One contributor expresses confusion about the notation and whether there might be a typo in an assignment suggesting T = T^-1. Ultimately, it is concluded that Lorentz transformations are special and do not equate to their own inverses, indicating a potential misunderstanding in the assignment. The conversation highlights the importance of careful notation and understanding in discussing Lorentz transformations.
yukcream
Messages
59
Reaction score
0
I am not sure wheather
matrix T^v_u = {T^u_v}^-1
or T^v_u = {T^v_u} is true?
T is a lorentz transformation for 4 vector~

Yuk
 
Physics news on Phys.org
Start by writing down the matrix representation of a general Lorentz transformation.

yukcream said:
I am not sure wheather
matrix T^v_u = {T^u_v}^-1

In matrix language, that is T^T=T^{-1}. In other words, you are asking if the transpose of T equals the inverse of T.

Try writing it out explicitly and see if it does.

or T^v_u = {T^v_u} is true?

Is there a typo here? Because here you just seem to be asking if T^{\mu}_{\nu} equals itself, unless there is something else implied by the { } braces.
 
It is great that you can understand my notation~ you are so smart!

It is my fault that I want to ask is T^v_u = {T^v_u} -1?

thanks for help
yuk
 
yukcream said:
It is great that you can understand my notation~ you are so smart!

Your notation is a lot like LaTeX, which is what I used to make my math symbols. So, I'm not really that smart. :-p

It is my fault that I want to ask is T^v_u = {T^v_u} -1?

OK, so now you're asking if T is equal to its own inverse. Again, try to write down the matrix and see if that is so.
 
Actually T is a special transformation~ called Lorentz transformation. In 4 vector case they are not equal~ but my lecturer asked me to prove T = T inverse~ I wonder is there is any typing error in his assignment given? or the position of the indexs may affect the result? They are not the same in fact!

yuk yuk
 
I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
Thread 'A cylinder connected to a hanging mass'
Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
Back
Top