Transformation Definition and 1000 Threads

  1. Rabindranath

    A Weyl transformation of connection and curvature tensors

    Given a Weyl transformation of the metric ##g_{\mu\nu} \rightarrow g'_{\mu\nu} = e^{\Omega(x)} g_{\mu\nu}##, I'm trying to find the corresponding connection ##\Gamma'^{\lambda}_{\mu\nu}##, and from that ##-## via the Riemann tensor ##R'^{\lambda}_{\mu\nu\kappa}## ##-## the Ricci tensor...
  2. M

    Transformation from de Sitter to flat spacetime coordinates

    Let me begin by stating that I'm aware of the fact that this is a metric of de Sitter spacetime, aka I know the solution, my problem is getting there. My idea/approach so far: in the coordinates ##(u,v)## the metric is given by $$g_{\mu\nu}= \begin{pmatrix}1 & 0\\ 0 & -u^2\end{pmatrix}.$$ The...
  3. L

    A Lorentz Transformations: Why We Need the Same $\gamma$

    If we have motion of system ##S'## relative to system ##S## in direction of ##x,x'## axes, Lorentz transformation suppose that observers in the two system measure different times ##t## and ##t'##. x'=\gamma(x-ut) x=\gamma(x'+ut') Why we need to use the same ##\gamma## in both relations? Why not...
  4. johnconner

    I Transformation matrix for an expanding space

    Hello. I am confused with this matter that how should we write the transformation matrix for an expanding space. consider a spacetime that is expading with a constant rate of a. now normally we scale the coordinates for expansion which makes the transformation matrix like this: \begin{pmatrix}...
  5. Q

    Checking the Lorentz transformation

    Homework Statement: This seemed at first glance very easy. But there appeared some confusion. A is moving to the right with velocity v with respect to B. The proper time for A is ##t_a=t_b\sqrt{1-v^2/c^2}##. And B is moving to the right with velocity u with respect to C. Proper time for B...
  6. Math Amateur

    MHB Norms for a Linear Transformation .... Browder, Lemma 8.4 ....

    I am reading Andrew Browder's book: "Mathematical Analysis: An Introduction" ... ... I am currently reading Chapter 8: Differentiable Maps and am specifically focused on Section 8.1 Linear Algebra ... I need some help in fully understanding Lemma 8.4 ... Lemma 8.4 reads as follows: In the...
  7. Athenian

    [Special Relativity] Lorentz Transformation and Boosts

    [BEGINNGING NOTICE] Before I begin showing my attempted solution, I would just like to quickly mention that this is a "repost" of the same question I had around a week ago. While I would usually use the "reply" function on the same thread, I believe that thread is getting pretty messy (sometimes...
  8. U

    How Can We Generalize the Lorentz Transformation to Two Dimensions?

    Summary: The problem is to generalize the Lorentz transformation to two dimensions. Relevant Equations Lorentz Transformation along the positive x-axis: $$ \begin{pmatrix} \bar{x^0} \\ \bar{x^1} \\ \bar{x^2} \\ \bar{x^3} \\ \end{pmatrix} = \begin{pmatrix} \gamma & -\gamma \beta & 0 & 0 \\...
  9. M

    Special Relativity question using Lorentz Transformation time dilation

    with distance between planets as 4x10^8m measured by you on the ship My attempt: t' = γ(t - ux/c^2) γ = 5/3 u = 0.8c t = 0.9s x = 4x10^8m answer is: -0.278 Therefore not possible My question is what if we traveled rightwards, from p2 to p1, would the answer change? Should my above information...
  10. Athenian

    [University Special Relativity] Lorentz Transformation and Boosts

    Unfortunately, I am not entirely confident of the above equations being able to do the trick and ultimately solve for the question. However, my guess is that using the equation written above for "boost", I could perhaps use ##v## and insert it into the ##x##-direction part of the matrix...
  11. dRic2

    Canonical transformation in classical mechanics

    I'm stuck from the beginning. I though I understood the difference between ## \delta## and ##d##, but apparently I was wrong, because I don't know how to exploit it here... Any hint would be greatly appreciated Thank Ric
  12. A

    Lorentz transformation of 4-acceleration

    I have been getting back to studying physics after a long break and decided to go through the problems in Rindler. But there is something I don't quite understand in this problem. To first answer the second part, Exercise II(12), I wrote $$\frac{du_2}{dt} = \frac{du_2}{du_2^\prime}...
  13. CBuphyx

    Fourier transformation (was: Homework title)

    Summary: Homework Statement: Fourier Transform momentum space to normAl space Homework Equations: F(k)=e^-b|k| show that g(x)=(b/pi)×(1/(x^2+b^2)Hello,I need to that given function Fouirier transform and function of graphic. Thank you😃 Homework Statement: Fourier Transform momentum space to...
  14. S

    I Find matrix of linear transformation and show it's diagonalizable

    The strategy here would probably be to find the matrix of ##F##. How would one go about doing that? Since ##V## is finite dimensional, it must have a basis...
  15. chaksome

    I Lorentz transformation for 3 frames (2 dimensions)

    I want to know why an else solution can not get the right answer. And want to know the way to correct this solution.Supposed that a frame S'' is moving in the lab frame at ##\beta_x## in the x-direction, ##\beta_y## in the y-direction, now I want to find out the Lorentz transformation between...
  16. Luke Tan

    I Transformation of the Christoffel Symbols

    In Landau Book 2 (Classical Field Theory & Relativity), he mentions that the transformation rules of the christoffel symbols can be gotten by "comparing the laws of transformation of the two sides of the equation governing the covariant derivative" I would believe that by the equations...
  17. R

    Using Y to Delta Transformation to Find Currents

    Can someone explain why I can't simply use a current divider once I've found the equivalent resistance and source current for the entire circuit? This would look like i0 = 0.044*(113.53/210). Req = 113.53. If it helps, the correct answers appear to be: i0 = 8.28 mA, i1 = 23.6 mA, i2 = 35.8 mA...
  18. S

    I Understanding linear transformation

    How can the function ##F(\mathbf{u})(t)=\mathbf{u}^{(n)}(t)+a_1\mathbf{u}^{(n-1)}(t)+...+a_n\mathbf{u}(t)##, where ##\mathbf{u}\in U=C^n(\mathbf{R})## (i.e. the space of all ##n## times continuously differentiable functions on ##\mathbf{R}##) be a linear transformation (from ##U##) to...
  19. arnau

    I Lorentz transformation for 3 frames

    A particle is moving in the lab frame ##S'## at ##\beta'_z##. I want to transform coordinates and momenta of the particle to a frame ##S## moving at ##\beta_0##. At time ##t = t' = 0##: $$z = \frac{z'} { \gamma_0 (1 - \beta'_z \beta_0) },\, \gamma\beta_z = \gamma_0 ( \gamma'\beta'_z -...
  20. D

    I Lorentz transformation of derivative and vector field

    I'm currently watching lecture videos on QFT by David Tong. He is going over lorentz invariance and classical field theory. In his lecture notes he has, $$(\partial_\mu\phi)(x) \rightarrow (\Lambda^{-1})^\nu_\mu(\partial_\nu \phi)(y)$$, where ##y = \Lambda^{-1}x##. He mentions he uses active...
  21. BillTre

    Will Pet Cloning become the Test Bed for Vertebrate Germline Transformation

    After reading this NY Times article on the possibility of cloning pets becoming a viable business in China, I was wondering if it might also become an area where germline modification might be more extensively tested and worked out. Why this might happen in China: large size of domestic pet...
  22. B

    Show that the Kronecker delta retains its form under any transformation

    Backstory - I have not been in school for 5ish years, and am returning to take some grad classes in the field of Solid Mechanics. I am freaking out a bit about the math (am rusty). I have not started class yet, but figured I would get my books and start working through problems. This problem...
  23. jk22

    B Deriving Lorentz Transformation: Wave Eq Invariance & General Relativity

    I read the Lorentz transformation can be obtained by solving the requirement of invariance of the wave equation. If one considers linear transformations this the same as the spacetime interval squared to be invariant. What are the other nonlinear transformations keeping the wave equation...
  24. B

    Fourier transformation of the Wavefunction in QM

    Hello Physics Forum, I am not sure what to to in this task, because the wavefunction is only given as A_0. Maybe someone can explain it to me. Thanks in Advance, B4ckflip
  25. WMDhamnekar

    MHB Transformation of random variable

    Hello, A discrete random variable X takes values $x_1,...,x_n$ each with probability $\frac1n$. Let Y=g(X) where g is an arbitrary real-valued function. I want to express the probability function of Y(pY(y)=P{Y=y}) in terms of g and the $x_i$ How can I answer this question? If any member...
  26. B

    Deriving Lorentz Transformations for Moving Reference Frames

    Problem Statement: Consider three frames Σ (x, y, z, t), Σ' (x', y', z', t'), and Σ'' (x'', y'', z'', t'') whose x, y, and z axes are parallel at each point in time stay. Σ' moves relative to Σ with velocity v1 along the x-axis. The system Σ'' moves relative to Σ' with the velocity v2 along the...
  27. M

    I What if the Jacobian doesn't exist at finite points in domain of integral?

    Consider a one to one transformation of a ##3##-##D## volume from variable ##(x,y,z)## to ##(t,u,v)##: ##\iiint_V dx\ dy\ dz=\int_{v_1}^{v_2}\int_{u_1}^{u_2}\int_{t_1}^{t_2} \dfrac{\partial(x,y,z)}{\partial(t,u,v)} dt\ du\ dv## ##(1)## Now for a particular three dimensional volume, is it...
  28. D

    I Deriving tensor transformation laws

    Hi, I'm worried I've got a grave misunderstanding. Also, throughout this post, a prime mark (') will indicate the transformed versions of my tensor, coordinates, etc. I'm going to define a tensor. $$T^\mu_\nu \partial_\mu \otimes dx^\nu$$ Now I'd like to investigate how the tensor transforms...
  29. P

    B Oxygen Transformation: A Puzzling Phenomenon

    Hi, guys. Just found a missing thing in my brain: if atomic oxygen will meet free electron somewhere why doesn't it become fluorine or even argone?
  30. GrafZeppelim

    I Linear transformation T: R3 -> R2

    Homework Statement Find the linear transformation [/B] T: R3 --> R2 such that: 𝑇(1,0,−1) = (2,3) 𝑇(2,1,3) = (−1,0) Find: 𝑇(8,3,7) Does any help please?
  31. Efeguleroglu

    Where's my mistake? (Lorentz Transformation for a moving spaceship)

    That's what I found. But the answer is arctan(sinθ*sqrt(1-v^2/c^2)/(cosθ+v/c))
  32. S

    I General Lorentz Transformation Explained: Visualize and Grasp It!

    Hi guys, I'm reading a book 'the theoretical minimum: special relativity and classical field theory'. In chapter 1.3, author explains the general Lorentz transformation. He said "Suppose you have two frames in relative motion along some oblique direction, not along any of the coordinate axes...
  33. karush

    MHB 17.1 Determine if T is a linear transformation

    nmh{2000} 17.1 Let $T: \Bbb{R}^2 \to \Bbb{R}^2$ be defined by $$T \begin{bmatrix} x\\y \end{bmatrix} = \begin{bmatrix} 2x+y\\x-4y \end{bmatrix}$$ Determine if $T$ is a linear transformation. So if...
  34. R

    I Beam-splitter transformation matrix

    The transformation matrix for a beam splitter relates the four E-fields involved as follows: $$ \left(\begin{array}{c} E_{1}\\ E_{2} \end{array}\right)=\left(\begin{array}{cc} T & R\\ R & T \end{array}\right)\left(\begin{array}{c} E_{3}\\ E_{4} \end{array}\right) \tag{1}$$ Here, the amplitude...
  35. N

    I Variable transformation for a multivariate normal distribution

    Hello. I would like to draw (sample) several random vectors x from a n-dimensional multivariate normal distribution. For this purpose I want to use C++ and the GNU Scientific Library function gsl_ran_multivariate_gaussian ...
  36. V

    I Geodesics under coordinate transformation

    I will start with an example. Consider components of metric tensor g' in a coordinate system $$ g'= \begin{pmatrix} xy & 1 \\ 1 & xy \\ \end{pmatrix} $$ We can find a transformation rule which brings g' to euclidean metric g=\begin{pmatrix} 1 & 0 \\ 0 & 1\\ \end{pmatrix}, namely...
  37. mertcan

    I Application of Box-cox transformation consecutively

    Hi everyone, as far as I have searched even we can obtain optimal lambda value to transform data to normal distributed with constant variance in box cox transformation method we may have not proper normal distributed data points. In short at the end we have just closer form of normal...
  38. Pencilvester

    I Lorentz Transformation Derivation: Assumptions Req'd?

    In deriving the Lorentz transformation, is it required to assume that the transformation to get from coordinate system ##\bf {x}## to ##\bf {x’}## should be the same as that to get from ##\bf {x’}## to ##\bf {x}## (with the simple correction of flipping the velocity)? If no, could someone...
  39. N

    I Block Diagonal Matrix and Similarity Transformation

    I am looking at page 2 of this document.https://ocw.mit.edu/courses/chemistry/5-04-principles-of-inorganic-chemistry-ii-fall-2008/lecture-notes/Lecture_3.pdf How is the transformation matrix, ν, obtained? I am familiar with diagonalization of a matrix, M, where D = S-1MS and the columns of S...
  40. A

    MHB Help Solving Linear Transformation Problem in R^2

    Hey i got a problem here but still without correction so if you guys can help me , thanks in advance I'm stuck there We have L : P -> R^2 L is a linear transformation with : B = \left\{1-x^{2},2x,1+2x+3x^{2} \right\} \; and \; B' = \begin{Bmatrix} \begin{bmatrix} 1\\-1 \end{bmatrix}...
  41. M

    Calculating field transformation

    Homework Statement Let ##\psi(x)=u(p)e^{-ipx}##, where $$ u((m,0)) = \sqrt{m}\begin{pmatrix} \xi\\\xi \end{pmatrix}\quad\text{where}\quad \xi = \sum_{s\in \{+,-\}}c_s\xi^s\quad \text{and}\quad \xi^+\equiv\begin{pmatrix} 1\\ 0 \end{pmatrix}\quad \xi^-\equiv\begin{pmatrix} 0\\ 1 \end{pmatrix}, $$...
  42. TheMercury79

    Diff.equation transformation by change of variables

    Homework Statement The assignment is to transform the following differential equation: ##x^2\frac {\partial^2 z} {\partial x^2}-2xy\frac {\partial^2 z} {\partial x\partial y}+y^2\frac {\partial^2 z} {\partial y^2}=0## by changing the variables: ##u=xy~~~~~~y=\frac 1 v##Homework Equations...
  43. karush

    MHB 13 is a linear transformation and .......Determine T

    Suppose that $T: \Bbb{R}^3 \rightarrow \Bbb{R}^3$ is a linear transformation and $$T \begin{bmatrix} 1 \\1 \\0 \\ \end{bmatrix} = \begin{bmatrix} 1 \\2 \\1 \\ \end{bmatrix}, \quad T \begin{bmatrix} 1 \\0 \\1 \\ \end{bmatrix} = \begin{bmatrix} 1 \\0 \\2 \\ \end{bmatrix}, \quad T...
  44. H

    I Confusion about the quantum field Lorentz transformation

    On page 59 of Peskin & Schroeder, there's a section on the lorentz transformation of field operators which I've attached. I'm confused about the part towards the end where he does a change of variable on the integration measure; it seems like he's only rewriting the lorentz-invariant integration...
  45. H

    I Symmetry transformation in Heisenberg vs Schrödinger Picture

    Symmetry transformations are changes in our point of view that preserve the possible outcomes of experiment: $$\Psi \rightarrow U(\Lambda) \Psi$$ In the Heisenberg picture, observables in a fixed reference frame evolve according to: $$P(t) = U^\dagger (t)PU(t)$$ while in the Schrodinger...
  46. CMJ96

    How to Diagonalize a Hamiltonian Using Bogoliubov Transformation?

    Homework Statement I'd like to diagonalise the following Hamiltonian for quasiparticle excitations in a Bose Einstein Condensate $$H= K_0 + \hat{K}_1 + \hat{K}_2 $$ where $$K_0 = \int d^3 r \left[ \phi_0 ^* (\hat{h}_0- \mu) \phi_0 + \frac{g}{2} |\phi_0| ^4 \right]$$ $$\hat{K}_1= \int d^3 r...
  47. A

    I Contravariant Vector Transformation in Spherical Polar Coordinates

    In a spherical polar coordinate system if the components of a vector given be (r,θ,φ)=1,2,3 respectively. Then the component of the vector along the x-direction of a cartesian coordinate system is $$rsinθcosφ$$. But from the transformation of contravariant vector...
  48. M

    Calculating different "kinds" of variations

    Homework Statement Let ##x## and ##x'## be two points from the Minkowski space connected through a Poincare transformation such that ##x'^\mu =\Lambda_{\nu}^\mu x^\nu+a^\mu## and ##u:\mathcal{M}\to \mathbb{K}=\mathbb{R}## or ##\mathbb{C}##, ##\mathcal{M}## the Minkowski space. We define: $$...
  49. A

    I What do we mean when we say something transforms "under"....

    What do we mean when we are talking about something that transforms under a representation of a group? Take for example a spinor. What is meant by: this two component spinor transforms under the left handed representation of the Lorentz group? When we talk about something that transforms...
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