Transformation Definition and 1000 Threads

  1. F

    Deriving the time dilation? equation of Lorentz transformation

    Homework Statement It is not an official question but a request for pointers. I am trying to derive the Lorentz time equation to understand the intuition behind it. My math skills are not very good so it might be an obvious question for you. Please see below for my attempt. The variables are...
  2. KleZMeR

    Gauge transformation has no effect on equation of motion

    I have a question about this classical invariance problem I'm working on. I'm almost done, and I understand the theory I think, so my question may seem a bit more math-oriented (it's been a few years since crunching equations). I have found that under a gauge transformation for a single particle...
  3. C

    Prove that s^2=(s')^2 using the Lorentz Transformation

    Homework Statement I am learning special relativity and we came across the invariant quantity s = x2 - (ct)2. Our professor wants us to prove it. I admit that this is a proof and belongs in the mathematics section but I didn't see an Algebra section and this is most easily identified by those...
  4. J

    Local Conformal Transformation: Coord or Metrical?

    Hello, I was wondering what the exact definition of conformal transformations is. This is a question in the context of Shape Dynamics. In Shape dynamics, time is viewed as a global parameter of the universe, and as such is invariant under spatial coordinate transformation. Part of the...
  5. R

    Derivation of Lorentz transformation (time)

    Hi all, I'm trying to derive that t=δ(t'+vx'/c^2) Using x'=δ(x-vt) then substituting for x=δ(x'+vt') I should be able to isolate t and solve the problem but I am getting to the following point after simplification and can't figure out where to go next...? x'= δ[δ(x'+vt')-vt] (isolate...
  6. S

    Adjoint transformation of gauge fields

    A gauge field W_\mu is known to transform as W_\mu\to W'_\mu=UW_\mu U^{-1} +(\partial_\mu U)U^{-1} under a gauge transformation U, where the first term UW_\mu U^{-1} means it transforms under the adjoint representation. Can anyone explain to me why it means a transformation under the adjoint...
  7. Z

    Transformation of variable (what happens with the area?)

    Homework Statement Dear friends, let U and V independent variables that are both defined on [-∏, ∏] and are uniformly distributed. If x = cos(U + V) and y = sin(U-V), what is the area where the variables X and Y are defined? Homework Equations U + V = arccos(x) U - V = arcsin(y) For a test...
  8. Z

    Canonical Transformation / Poisson Brackets

    Question: (A) Show that the following transformation is a canonical transformation: Q = p + aq P = (p - aq)/(2a) (B) Find a generating functions for this transformation. Attempt of Solution: Alright, so this seems to be a very straight forward problem. Transformations are canonical...
  9. M

    Coupled equation transformation

    can anyone help explain the mechanism of coupled equation transformation and when and how can i transform similar equations?
  10. K

    What is the Geometrical Proof for the Coordinate Transformation Formula?

    Homework Statement Prove: \cos\alpha\cdot\cos\alpha'+\cos\beta\cdot\cos\beta'+\cos\gamma\cdot\cos \gamma'=\cos\theta See drawing Snap1 Homework Equations None The Attempt at a Solution See drawing Snap2. i make the length of the lines 1 and 2 to equal one, for simplicity. The...
  11. Mogarrr

    Negative binomial transformation and mgf

    Imo, this problem is crazy hard. Homework Statement Let X have the negative binomial distribution with pmf: f_X(x) = \binom{r+x-1}{x}p^{r}(1-p)^{x}, x=0.1.2..., where 0<p<1 and r is a positive integer. (a) Calculate the mgf (moment generating function) of X. (b) Define a new...
  12. Greg Bernhardt

    What is the Lorentz transformation

    [SIZE="4"]Definition/Summary A Lorentz transformation is the relation between the coordinates of two inertial observers who use the same event as their origin of coordinates. A Lorentz boost is a Lorentz transformation with no rotation (so that both observers use the same coordinate-name...
  13. T

    Deriving the Lorentz Transformation

    Hello everyone. I am attempting to teach myself about special relativity, and have learned a derivation for the Lorentz transformation. Before I go any farther I want to clear up the parts I don't understand right now and check that I am correct about the parts I do understand. Here I will...
  14. D

    Schwartz - Christoffel transformation: point at infinity confusion

    We know that the derivative of the general Schwartz - Christoffel map (function) is: f'(z) = λ(z - x_1)^{a_1}...(z-x_n)^{a_n} Question: In various sources around the web, it is mentioned that x_n can be taken to be the "point at infinity", and the last factor can be removed from the above...
  15. C

    Does Integral Transformation Apply in Equality of Modified Bessel Functions?

    Change of variables for integral Homework Statement Determine whether the following equality holds: \displaystyle\int_0^{\infty} \frac{e^{-\dfrac{(x^2+4z^2)}{4z}}}{2z} \, \mathrm{d}z = \displaystyle\int_0^{\infty} \frac{e^{-\dfrac{(1+z^2)x}{2z}}}{2z} \, \mathrm{d}z, \forall x,z \in...
  16. L

    Transformation of Stress (Mech. Materials)

    Homework Statement Question is attached Homework Equations σ(x) = 0 σ(y)= P/A t(xy)= Tc/j The Attempt at a Solution I know how to do the stress transformation, but my only issue is noticing why σ(x)= 0, I can't see it, can someone help me.
  17. Mr-R

    Affine connection transformation

    Dear All, I am teaching myself tensors for the first time. I am using D'Inverno's book and got stuck at page 73. Basically, he says: demand that the first term on the left of the equation to be a type (1,1) tensor. Then he gets the affine connection transformation. I basically wrote the...
  18. Q

    Solving the Twin Paradox with General Relativity

    I have read some basics knowledge about General Relativity and I see that it deal perfectly with gravity. But what about accelerated frames? Is there something similar to Lorentz Transformation for accelerated frame in General Relativity? (so that i can solve, maybe, the general twin paradox)...
  19. 159753x

    Intuition for imaginary part of Fourier Transformation?

    Hi there, I'm having trouble understanding the Fourier transform of a function where the result in the frequency domain has imaginary components. For example, if you take the Fourier transform of Sin[t] , the result is I Sqrt[\[Pi]/2] DiracDelta[-1 + \[Omega]] - I Sqrt[\[Pi]/2]...
  20. B

    Derivation of Noether currents under Lorentz Transformation

    Is there anywhere I can see the explicit derivation for a massless real scalar and for the EM field? thank you.
  21. C

    Transformation of generator under translations

    Homework Statement Let us study the subgroup of the Poincare group that leaves the point ##x=0## invariant, that is the Lorentz group. The action of an infinitesimal Lorentz transformation on a field ##\Phi(0)## is ##L_{\mu \nu}\Phi(0) = S_{\mu \nu}\Phi(0)##. By use of the commutation...
  22. J

    Maxwell's Equations and Lorentz Transformation

    Hi! I'm having problems with this homework my professor gave us this morning: Prove that Maxwell's equations is invariant under Lorentz Transformation. I'm just currently in third year, and we haven't been taught tensors yet. The extent of what I know mathematically is only until gradient...
  23. Seydlitz

    Notation used in matrix representation of linear transformation

    Hello guys, Let ##T: \mathbb{R^2} \to \mathbb{R^2}##. Suppose I have standard basis ##B = \{u_1, u_2\}## and another basis ##B^{\prime} = \{v_1, v_2\}## The linear transformation is described say as such ##T(v_1) = v_1 + v_2, T(v_2) = v_1## If I want to write the matrix representing ##T##...
  24. G

    What is the Lorentz Transformation Equation and its Use in Relativity?

    I really don't understand what it is and what is the use of constant, like in this equation of transformation. x=k(x' + vt). The equation can also be good if it is just like this, x=x' + vt Thank you.
  25. H

    Lorentz transformation And Einstein's Laws.

    To=(time of moving object.) T=(Time of standing object.) ^=power of number. sqrt=square of number.(x^1/2)Law of einstein say: T= To / ( sqrt( 1 - u^2/c^2 ) ) Lorentz law say: T= (To + u*Xo/c^2) / ( sqrt( 1 - u^2/c^2 ) )Why there is difference?? Is for other things?? I thought is for the same...
  26. P

    Dirac Spinor Transformation (Ryder)

    Homework Statement This complies when I type it in my Latex editor, but not on here. If you could either let me know how to fix that or copy and paste what I have into your own editor to help, that'd be great. Thanks! While Ryder is setting up to derive a transformation rule for Dirac...
  27. M

    Adjoint transformation statement.

    I have doubts regarding a statement related to the following proposition: Let ##(V,<,>)## be a finite dimensional vector space equipped with an inner product and let ##f:V \to V## be a linear transformation, then the following statements are equivalent: 1)##<f(v),f(w)>=<v,w>## for all ##v,w \in...
  28. J

    Transformation Y-Δ with matrix?

    See: http://en.wikipedia.org/wiki/Y-%CE%94_transform#Basic_Y-.CE.94_transformation Is possible to express the following relationships: using matrix?
  29. Q

    MHB Commutativity in the linear transformation space of a 2 dimensional Vector Space

    A variant of a problem from Halmos : If AB=C and BA=D then explain why (C-D)^2 is commutative with all 2x2 matrices if A and B are 2x2 matrices. This result does not hold for any other nxn matrices where n > 2. Explain why. Edit: I tried to show that ((C-D)^2) E - E((C-D)^2) is identically...
  30. S

    Some examples of Möbius transformation

    Homework Statement Find Möbius transformation that maps: a) circle ##|z+i|=1## into line ##Im(z)=2## b) circle ##|z-i|=1## into line ##Im(z)=Re(z)## c) line ##Re(z)=1## into circle ##|z|=2##Homework Equations ##f(z)=\frac{az+b}{cz+d}##The Attempt at a Solution a) Firstly to move the circle...
  31. J

    Transformation behavior of the gradient

    Hi All, I think I have confused myself ... perhaps you can tell me where my reasoning is wrong. The idea is that in general coordinates the partial derivative of a vector, \frac{\partial A^i}{\partial x^j}, is not a tensor because an additional term arises (which is the motivation for...
  32. M

    Unitary transformation of pure states to other pure states

    Is it true that there always exist a unitary matrix that can take a state vector of an arbitrary pure state to another arbitrary pure state ? (of course assuming same hilbert space). If true, how do we prove it ? it look like it is true via geometrical arguments but i have not been able to...
  33. N

    Linear transformation and change of basis

    Homework Statement Let B = {(1, -2),(2, -3)} and S be the standard basis of R2 and [-8,-4;9,4] be a linear transformation expressed in terms of the standard basis? The Attempt at a Solution 1) What is the change of basis matrix PSB ? 1,2 -2,-3 2)What is the change of...
  34. J

    Geometrical interpretation of this coordinate transformation

    How can I geometrically interpret this coordinate transformation (from x,y space to \check{x},\check{y} space)? x = \check{x}cos(β) - \check{y}sin(β) y = \frac{1}{2}(\check{x}2 -\check{y}2)sin(2β) -\check{x}\check{y}cos (2β)
  35. S

    Help with linear transformation problem with variables

    Let L: R3 -> R3 be L(x)= \begin{pmatrix} x1+x2\\ x1-x2\\ 3x1+2x2 \end{pmatrix} find a matrix A such that L(x)=Ax for all x in R2 From what I understand I need to find the transition matrix from the elementary to L(x). However it is'nt a square matrix and it has variables instead of numbers...
  36. S

    Find power series if you know its laplace transformation

    Homework Statement a) Determine power series ##\sum _{n=0}^{\infty }a_nt^n## if you know that its laplace transformation is ##-s^{-1}e^{-s^{-1}}## b) Determine function ##g## that this power series will be equal to ##J_0(g(t))##Homework Equations The Attempt at a Solution Hmmm, I am having...
  37. S

    Laplace transformation: system of DE

    Homework Statement Let ##y_1^{'}+y_1=y_2##, ##y_2^{'}+5y_2=y_3##, ##y_3^{'}+y_3=f## and ##y_1(0)=y_2(0)=y_3(0)=0##. Find ##Y_1(s)## in terms of ##F(s)##. Homework Equations The Attempt at a Solution I am completely lost here. I tried to rewrite the system so that I would...
  38. S

    Laplace Transform for Functions: 5cos(7t+π/4) and e^(3t)sintcost

    Homework Statement Find Laplace transformation for functions ##f(t)##: a) ##5cos(7t+\pi /4)## b) ##e^{3t}sintcost##Homework Equations The Attempt at a Solution a) I know that for ##cos(\omega t)## the laplace is ##\frac{s}{s^2+\omega ^2}## but what can I do with that ##\pi /4## ? I believe I...
  39. P

    Transformation of acceleration between two reference frames

    hello i want to derive the Transformation of acceleration between two reference frames i searched in internet and found a book but i don't understand just one step i attach a picture so you can see what i found in the internet my problem is eq. (1.10) \begin{align}du=\frac{dU}{\gamma...
  40. P

    Wave equation and fourier transformation

    Homework Statement utt=a2uxx Initial conditions: 1)When t=0,u=H,1<x<2 and u=0,x\notin(1<x<2) 2)When t=0,ut=H,3<x<3 and u=0,x\notin(3<x<4) The Attempt at a Solution So I transformed the first initial condition \hat{u}=1/\sqrt{2*\pi} \int Exp[-i*\lambda*x)*H dx=...
  41. E

    Showing that a linear transformation from P3 to R4 is an isomorphism?

    I have a linear transformation, T, from P3 (polynomials of degree ≤ 3) to R4 (4-dimensional real number space). I have a second linear transformation, U, from R4 back to P3. In the first step of this four-step problem, I have shown that the composition TU from R4 to R4 is the identity linear...
  42. adjacent

    Matrix and transformation problem

    Let there be a triangle with coordinates A(2,2) , B(5,2) and C(5,4) I have learned two ways to shear an object(x-axis invariant) in the Cartesian coordinate system. The first way is to find the coordinate vector of a point and multiply the y-component of the vector by the shear factor(2)(Don't...
  43. A

    Galilean transformation problem (Speed)

    Homework Statement A girl is riding a bicycle along a straight road at constant speed, and passes a friend standing at a bus stop (event #1). At a time of 60 s later the friend catches a bus (event #2) If the distance separating the events is 126 m in the frame of the girl on the bicycle...
  44. K

    Given a transformation of the plane F(x,y) = (2x+y,x-2y), find F^-1.

    Homework Statement Given a transformation of the plane F(x,y) = (2x+y,x-2y), find F-1. Homework Equations Actually this exercise had an item (a) which I had to prove this is a transformation. So I proved this function is injective and surjective. I know F(x,y) = (u,v) IFF F-1(u,v) =...
  45. Feodalherren

    Jacobian transformation and 2D curl

    Umm what just happened? I understand as far as u=x+y and v = y/x and when he does the 2d curl. What I don't get is the step thereafter when he flips it. How does he know to flip it? Further, when he flips it wouldn't that make the dvdu inside the integral cancel and hence leave him with dxdy?
  46. Feodalherren

    Jacobian transformation, find new limits

    Homework Statement Homework Equations The Attempt at a Solution What I don't understand is how I'm supposed to find those limits for U and V. That's not at all what I'm getting. I've tried solving for the max and min x,y coordinates from the given graphs but that doesn't yield...
  47. C

    Lorentz Transformation of Velocity 4 Vector Help

    So i am working on a question, which is beyond my knowledge of Lorentz transformations and some help is greatly appreciated. I have a 4 velocity, u=γ(v vector,c) and its transformation properties are the standard lorentz boost. I don't quite understand how I am supposed to do this given that...
  48. M

    Simple question concerning unitary transformation

    Is the transformation of an operator under INFINITESIMAL unitary transformation, U^-1AU or UAU^-1?? I saw that two books defined it differently?
  49. N

    Linear transformation (minor clarification)

    Homework Statement The Attempt at a Solution I don't think I'm interpreting the question correctly. Maybe someone can point me in the right direction? There are 2 conditions: if y =/=0 then f(x,y) = x^2/y and if y=0 then f(x,y) = 0 Let u =(1,1) and v = (1,1) f(v) = f(1,1) =...
  50. N

    Simple Linear Transformation: Proving Linearity with (1,1) Vectors

    Homework Statement f(x,y) -> |x+y| The Attempt at a Solution The answer is that the above transformation is not linear but my working shows otherwise. Here's my go: let u = (1,1) and v = (1,1) f(u) = f(1,1) = 2 f(v) = f(1,1) = 2 f(u) + f(v) = 4 f(u+v) = f(2,2) = 4...
Back
Top