Transformation Definition and 1000 Threads

  1. K

    Lorentz Transformation Question

    Homework Statement For an event occurring at (x,t), consider the quantity I = x^2 - (ct)^2 Find a simple expression for this in the S' frame: I' = x'^2 - (ct')^2 How are I and I' related, and why is this noteworthy? The Attempt at a Solution So the question is under "Lorentz Transformation"...
  2. D

    Identifying time and/or amplitude transformations

    So the question looks like this: Identify the time and/or amplitude transformations that must be applied to the signal x(t) in order to obtain each of the signal specified below. Choose the transformations such that time shifting precedes time scaling and amplitude scaling precedes amplitude...
  3. K

    Lorentz Transformation, Time Dilation, Length Contraction

    Homework Statement [/B] A spaceship is approaching Earth from the far side of the sun. The Earth and sun are 8 light minutes apart and the ship is traveling at .8c. Two events are indisputable. 1) the ship is at the sun 2) the ship is at the earth. Assume that the Earth and sun are at rest...
  4. S

    Scale factor of special conformal transformation

    Homework Statement (From Di Francesco et al, Conformal Field Theory, ex .2) Derive the scale factor Λ of a special conformal transformation. Homework Equations The special conformal transformation can be written as x'μ = (xμ-bμ x^2)/(1-2 b.x + b^2 x^2) and I need to show that the metric...
  5. K

    I Galilean transformation paradox help

    I'm getting quite stuck on this problem here. Galileo said that Xb = Xa - V*Ta. (This follows from dv = dx/t --> Xa - Xb = t*dv --> the above formula) Thus, it is concluded Xa = Xb + V*Ta, but why? In my thought experiment the objects are moving relative to each other, thus if A is moving away...
  6. K

    Calculating Distance and Time Using Lorentz Transformation

    Homework Statement A rocket is traveling toward a galaxy with speed v. a) If NASA says that distance from Earth to the galaxy is d, what is the distance d' from Earth to the galaxy according to the astronauts? b) The astronauts experience a travel time to the galaxy t' and NASA records the...
  7. E

    Field transformation laws - Relativity

    Homework Statement The electric and magnetic fields of a 1 Coulomb charge Q are measured by a pair of field measuring instruments. From the perspective of observers in frame O, the charge is at rest at the origin and one of the field-measuring devices is also at rest, with position (x,y,z) =...
  8. R

    I Change of variables many-to-many transformation

    With the change of variables-method for a many-to-one transformation function Y = t(X), what's the logic behind summing the different densities for the roots of x = t^-1(y)? Probabilities should be ok to add, but densities? Also, is there no way to extend this method for many-to-many...
  9. Battlemage!

    I Coordinate transformation of a vector of magnitude zero

    Is there some geometry in which a coordinate transformation of a vector of magnitude zero transforms to a vector that does not have a zero magnitude? Since the formula for the magnitude of a vector is √(x12+x22+...xn2), I can see no way for it to have magnitude zero unless every component is...
  10. Zeeree

    Mobius transformation for the first quadrant

    Homework Statement Find the images of the following region in the z-plane onto the w-plane under the linear fractional transformations The first quadrant ##x > 0, y > 0## where ##T(z) = \frac { z -i } { z + i }## Homework EquationsThe Attempt at a Solution [/B] So for this, I looked at the...
  11. O

    I Vector to scalar potential, transformation of fields

    Hey guys. So, as i was going through Griffith's Electrodynamics, and i came across this problem: In the solutions: How to they actually get to that expression for V = (V(bar)+vAx(bar) )Ɣ? I understand everything after that, but this just made me very confused. How do they get this from the...
  12. RJLiberator

    Legendre Transformation of f(x) = x^3

    Homework Statement [/B] Find the Legendre Transformation of f(x)=x^3 Homework Equations m(x) = f'(x) = 3x^2 x = {\sqrt{\frac{m(x)}{3}}} g = f(x)-xm The Attempt at a Solution I am reading a quick description of the Legendre Transformation in my required text and it has the example giving for...
  13. V

    I Active vs Passive Lorentz transformation

    Hi. First, excuse my English. In my lecture notes on classical electrodynamics, we are introduced to the Lorentz transformations: a system S' moves relative to a system S with positive veloticy v in the x-axis (meassured in S), spatial axis are parallel, origin of times t and t' coincide...
  14. T

    Estimating the final pressure of a transformation

    Homework Statement If the Helmholtz Free Energy remains constant, estimate the final pressure of 1.0mol of an ideal gas in the following transformation: (1.0atm, 300k) → (pfinal, 600k). Given Sgas = R. Homework Equations A = U - TS dA = -SdT - pdV The Attempt at a Solution If the Helmholtz...
  15. G

    I Lorentz Transform: Justifying Use in Acceleration

    In a standard problem of an electron released from the negative plate in an E field between 2 parallel plates in which the velocity must be determined why can the Lorentz transformation be used (involving v^2/c^2) when the electron is undergoing acceleration and there is nothing in the...
  16. physicality

    I Conformal transformation of the line element

    Let us see how the line element transforms under conformal transformations. Consider the Minkovski metric gij, a line element ds2=dxigijdxj, and a conformal transformation δk(x)=ak + λ xk + Λklxl + x2sk - 2xkx⋅s We have δ(dxk)=dδ(x)k=λ dxk + Λkldxl + 2 x⋅dx sk - 2dxkx⋅s - 2xkdx⋅s And so the...
  17. Stollaxel Stoll

    B Velocity transformation from spherical to cartesian coords

    I cant't figure out how to transform ##\dot{r}##, ##\dot{\theta}##, ##\dot{\phi}## in spherical coordinates to ##\dot{x}##, ##\dot{y}##, ##\dot{z}## in cartesian coordinates (the dot is Newton's notation for the first time-derivative which is the angular velocity and velocity). I have no...
  18. C

    A Transformation properties of the Christoffel symbols

    If you want to define a covariant derivative which transforms correctly, you need to define it as ##\nabla_i f_j = \partial_i f_j - f_k \Gamma^k_{ij}##, where ##\Gamma^k_{ij}## has the transformation property ##\bar{\Gamma}^k_{ij} = \frac{\partial \bar{x}_k}{\partial x_c}\frac{\partial...
  19. D

    Linear Transformation R4 to R4: KerT + ImT = R4

    Homework Statement Let T be a Linear Transformation defined on R4 ---> R4 Is that true that the following is always true ? KerT + ImT = R4Homework EquationsThe Attempt at a Solution Since every vector in R4 must be either in KerT or the ImT, so the addition of those subspace contains R. and ofc...
  20. G

    I Christoffel symbols transformation law

    In Carroll's GR book (pg. 96), the transformation law for Christoffel symbols is derived from the requirement that the covariant derivative be tensorial. I think I understand that, and the derivation Carroll carries out, up until this step (I have a very simple question here, I believe-...
  21. R

    I Vector Transformation Law and Vector Spaces: Is it Abuse?

    Typically an element of a vector space is called a vector, but Carroll's GR book repeatedly refers to elements of tangent spaces as "transforming as a vector" when they change coordinates as Vμ = ∂xμ/∂xν Vν. However, dual vectors are members of vector spaces (cotangent space) but obey ωμ =...
  22. L

    What Conditions Ensure Symmetry in a System of Nonlinear Differential Equations?

    Homework Statement System of equations \frac{du_j}{dt}=u_{j+1}+u_{j-1}-2u_j-\frac{K}{2 \pi}\sin(2\pi u_j)+\bar{F}+F_{ac}\cos(2\pi \nu_o t) where ##j=1,2,3,4##. So ##\{u_j\}## is set of coordinates. If we apply symmetry transformation \sigma_{r,m,s}\{u_j(t)\}=\{u_{j+r}(t-\frac{s}{\nu_0})\} how...
  23. M

    Linear Algebra: Matrix Transformation

    Homework Statement Find the matrix that represents a rotation counterclockwise around the origin by 75 degrees followed by a reflection about the x-axis Homework Equations I know that for A rotated counter clockwise you use the 2x2 matirx [cos(theta), -sin(theta)] [sin(theta, cos(theta)] and...
  24. mertcan

    I Jacobian matrix generalization in coordinate transformation

    hi, I always see that jacobian matrix is derived for just 2 dimension ( ıt means 2x2 jacobian matrix) in books while ensuring the coordinate transformation. After that kind of derivation, books say that you can use same principle for higher dimensions. But, I really wonder if there is a proof...
  25. nomadreid

    I Transformation needed to fit three conditions

    I am working in ℂ3 in this question. (If it will make it easier, we can work in a bounded subspace.) Suppose you have, in each of the three complex planes whose Cartesian product make up the space in question, a set of points. (You do not have knowledge of generators of these sets, or whether...
  26. T

    When can I use source transformation?

    Homework Statement I'm asking this question because I was trying to apply the method to a Thevenin Eq problem and the answer came out wrong. Also one more related question. According to the textbook, when a current source is connected both in series with a resistor and in parallel with...
  27. S

    The restricted canonical transformation group

    Homework Statement Show that the set of restricted canonical transformation forms a group. Verify this statement once using the invariance of Hamilton's principle under canonical transformation, and again using the symplectic condition. Homework Equations (Invariance of Hamilton's principle...
  28. A

    A The de Broglie wavelength: What happens in the case of a frame change?

    I have a problem to understand the de Broglie wavelength. We know that also particles undergo scattering and interference at a double slit. The interference pattern is calculated by the use of the de Broglie wavelength which is defined as lambda = h / p ; p is the momentum of the particle. This...
  29. D

    Show that the T is a linear transformation

    Homework Statement T:R2[x] --> R4[x] T(f(x)) = (x^3-x)f(x^2) Homework EquationsThe Attempt at a Solution Let f(x) and g(x) be two functions in R2[x]. T(f(x) + g(x)) = T(f+g(x)) = (x^3-x)(f+g)(x^2) = (x^3-x)f(x^2) + (x^3-x)g(x^2) = T(f(x)) + T(g(x)). let a be scalar in R: aT(f(x)) =...
  30. Artlav

    Ray transformation of a 3d lens?

    Greetings. I'm working on a raytracer, and got stuck with trying to model a lens analytically. Given is a thin lens at position p with the axis n, radius r and a focal distance f, a ray hits it at position p1 going in the direction d. Which way would the ray be going on the other side of the...
  31. R

    Relative Velocity of Two Rockets and the Earth

    Homework Statement Two rockets A and B are moving away from the Earth in opposite directions at 0.85c and -0.75c respectively. How fast does A measure B to be travelling? Now I have worked out v = -0.85-0.75/(1- -0.85*-0.75) = -0.997. This is correct. Now I would like to work it out backwards...
  32. P

    Finding a matrix for a linear transformation

    'Homework Statement Find the matrix A' for T: R2-->R2, where T(x1, x2) = (2x1 - 2x2, -x1 + 3x2), relative to the basis B' {(1, 0), (1, 1)}. Homework Equations B' = {(1, 0), (1, 0)} so B'-1 = {(1, -1), (0, 1)}. The Attempt at a Solution I'm confused at what exactly a transform matrix...
  33. P

    Linear transformation representation with a matrix

    Homework Statement For the linear transformation T: R2-->R2 defined by T(x1, X2) = (x1 + x2, 2x1 - x2), use the matrix A to find T(v), where v = (2, 1). B = {(1, 2), (-1, 1)} and B' = {(1, 0), (0, 1)}.Homework Equations T(v) is given, (x1+x2, 2x1-x2) The Attempt at a Solution Okay, I see...
  34. i_hate_math

    Linear Transformation and Inner Product Problem

    Homework Statement Consider the vector space R2 with the standard inner product given by ⟨(a, b), (c, d)⟩ = ac + bd. (This is just the dot product.) PLEASE SEE THE ATTACHED PHOTO FOR DETAIlS Homework Equations T(v)=AT*v The Attempt at a Solution I was able to prove part a. I let v=(v1,v2)...
  35. S

    Show that T is a nonlinear transformation

    1. Show that T isn't a linear transformation and provide a suitable counterexample. ##T \begin{bmatrix}x\\y \end{bmatrix} = \begin{bmatrix}x - 1 \\ y + 1 \end{bmatrix}## 2. The attempt at a solution ##\text{let}\, \vec{v} = \begin{bmatrix}0\\0 \end{bmatrix}. \text{Then,}## ##T(\vec{v}) =...
  36. J

    I Are the Lorentz transformation formulas on wikipedia correct?

    They seem to defy the most fundamental principle of SR. The first postulate/equivalence principle. According to wikipedia, we get Lorentz boost (x direction) and slightly different formulas for the inverse Lorentz boost "This "trick" of simply reversing the direction of relative velocity...
  37. KT KIM

    I Matrix Representation of Linear Transformation

    This is where I am stuck. I studied ordered basis and coordinates vector previous to this. of course I studied vector space, basis, linear... etc too, However I can't understand just this part. (maybe this whole part) Especially this one which says [[T(b1)]]c...[[T(bn)]]c be a columns of...
  38. S

    Lorentz transformation of electric and magnetic fields

    Homework Statement Using the tensor transformation law applied to ##F_{\mu\nu}##, show how the electric and magnetic field ##3##-vectors ##\textbf{E}## and ##\textbf{B}## transform under (a) a rotation about the ##y##-axis, (b) a boost along the ##z##-axis. Homework Equations The Attempt at...
  39. Dr. Who

    I Mass to Energy Transformation for ordinary Chemical reaction

    Hi, My Modern Physics lecturer is of the opinion that the energy dissipated during exothermic reactions is due to infinitesimally small change in mass of the reactants. Similarly, he said that an infinitesimally small part of the food we eat gets converted into the energy using which we perform...
  40. G

    MHB How to define this linear transformation

    > Admit that $V$ is a linear space about $\mathbb{R}$ and that $U$ and $W$ are subspaces of $V$. Suppose that $S: U \rightarrow Y$ and $T: W \rightarrow Y$ are two linear transformations that satisfy the property: > $(\forall x \in U \cap W)$ $S(x)=T(x)$ > Define a linear transformation $F$...
  41. G

    I How this defines a linear transformation

    Admit that V is a linear space about \mathbb{R} and that U and W are subspaces of V. Suppose that S: U \rightarrow Y and T: W \rightarrow Y are two linear transformations that satisfy the property: (\forall x \in U \cap W) S(x)=T(x) Define a linear transformation F: U+W \rightarrow Y that...
  42. S

    Investigations into the infinitesimal Lorentz transformation

    Homework Statement [/B] A Lorentz transformation ##x^{\mu} \rightarrow x'^{\mu} = {\Lambda^{\mu}}_{\nu}x^{\nu}## is such that it preserves the Minkowski metric ##\eta_{\mu\nu}##, meaning that ##\eta_{\mu\nu}x^{\mu}x^{\nu}=\eta_{\mu\nu}x'^{\mu}x'^{\nu}## for all ##x##. Show that this implies...
  43. O

    A Ellipse of transformation from spherical to cartesian

    Hi, I have to resample images taken from camera, whose target is a spherical object, onto a regular grid of 2 spherical coordinates: the polar and azimutal angles (θ, Φ). For best accuracy, I need to be aware of, and visualise, the "footprints" of the small angle differences onto the original...
  44. S

    A Field transformation under an active transformation

    Under the infinitesimal translation ##x^{\nu} \rightarrow x^{\nu}-\epsilon^{\nu}##, the field ##\phi(x)## transforms as ##\phi_{a}(x) \rightarrow \phi_{a}(x) + \epsilon^{\nu}\partial_{\nu}\phi_{a}(x)##. I don't understand why the field transforms as above. Let me try to do the math. The...
  45. N

    Bogoliubov Transformation Presentation

    Hi I have to give a presentation on Bogoliubov transformations to my undergrad solid state physics class. The presentation is only supposed to be 15ish minutes long, and defining them alone will take a few minutes. Because of the time constraint, I was wondering if anyone knew of a simple...
  46. Zarmina Zaman Babar

    A Fourier Transform of Piecewise linear spline wavelet

    Fourier Transform of Piecewise linear spline wavelet is defined by 1-|t|, 0<t<1; 0, otherwise, is (sinc(w/2))^2. Can anyone please show me the steps. Thanks
  47. L

    Similarity Transformation Involving Operators

    Homework Statement Virtually all quantum mechanical calculations involving the harmonic oscillator can be done in terms of the creation and destruction operators and by satisfying the commutation relation \left[a,a^{\dagger}\right] = 1 (A) Compute the similarity transformation...
  48. A

    I Composite Galilean transformation in 2 dimensions

    The Galilean transforms for rotations, boosts and translations in 2D are the follows: Rotations: x' = xcosθ + ysinθ y' = -xsinθ + ycosθ Boosts: x' = x - vxt y' = y - vyt Translations: x' = x - dx y' = y - dx I wanted to combine these into a single pair of equations, so my first thought was...
  49. H

    Deriving the Lorentz Transformation from the Homogeneity of Spacetime

    Homework Statement Show that the isotropy and homogeneity of space-time and equivalence of different inertial frames (first postulate of relativity) require that the most general transformation between the space-time coordinates (x, y, z, t) and (x', y', z', t') is the linear transformation...
  50. kolawoletech

    A Most General form of Canonical Transformation

    How do I go about finding the most general form of the canonical transformation of the form Q = f(q) + g(p) P = c[f(q) + h(p)] where f,g and h are differential functions and c is a constant not equal to zero. Where (Q,P) and (q,p) represent the generalised cordinates and conjugate momentum in...
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