What is Parallel transport: Definition and 70 Discussions

In geometry, parallel transport is a way of transporting geometrical data along smooth curves in a manifold. If the manifold is equipped with an affine connection (a covariant derivative or connection on the tangent bundle), then this connection allows one to transport vectors of the manifold along curves so that they stay parallel with respect to the connection.
The parallel transport for a connection thus supplies a way of, in some sense, moving the local geometry of a manifold along a curve: that is, of connecting the geometries of nearby points. There may be many notions of parallel transport available, but a specification of one — one way of connecting up the geometries of points on a curve — is tantamount to providing a connection. In fact, the usual notion of connection is the infinitesimal analog of parallel transport. Or, vice versa, parallel transport is the local realization of a connection.
As parallel transport supplies a local realization of the connection, it also supplies a local realization of the curvature known as holonomy. The Ambrose–Singer theorem makes explicit this relationship between curvature and holonomy.
Other notions of connection come equipped with their own parallel transportation systems as well. For instance, a Koszul connection in a vector bundle also allows for the parallel transport of vectors in much the same way as with a covariant derivative. An Ehresmann or Cartan connection supplies a lifting of curves from the manifold to the total space of a principal bundle. Such curve lifting may sometimes be thought of as the parallel transport of reference frames.

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  1. O

    Understanding parallel transport (Gen Rel)

    Homework Statement If I have a two curves \gamma_{1}, \gamma_{2} with the same start and end points, lying on a smooth manifold M. For a vector v at the "start" point, if I parallelly transport down both curves to the "end" point, will the two vectors at the "end" be different or the same...
  2. J

    Calculating Vector Parallel Transport & Berry's Phase

    If I know the metric everywhere, and I specify a closed path, how can I calculate whether a vector parallel transported around the path will return to being the same vector or not? I assume there is some simple integral to describe this, but I'm not sure how to write it down. Unfortunately...
  3. M

    Parallel transport on circle

    I'm trying to understand parallel transport and I'm stuck. The example given is if you have a unit sphere and you take one of the latitudes (not the equator), take at a point on the latitude the tangent vector to the curve, and parallel transport it around the curve. I don't understand why the...
  4. L

    Parallel Transport: Constancy of Magnitudes & Angles Along Geodesic

    A vector field Y is parallely propagated (with respect to the Levi-Civita connection) along an affinely parameterized geodesic with tangent vector X in a Riemannian manifold. Show that the magnitudes of the vectors X, Y and the angle between them are constant along the geodesic.
  5. D

    Understanding the Parallel Transport Problem in Riemannian Geometry

    Hi! I've finally decided to tackle a diff geom book, but I'm having trouble with this Problem 4/Chapter 2 from Do Carmo's Riemannian Geometry: Let M^2\subset R^3 be a surface in R^3 with induced Riemannian metric. Let c:I\rightarrow M be a differentiable curve on M and let V be a vector...
  6. Rasalhague

    Currently understand by parallel transport

    This is what I currently understand by parallel transport. The definitions I've read don't talk about it in quite this way, as a vector field, but I think this is equivalent to them: Given a tangent vector V0 at some point P0, construct a vector field along an oriented curve P(?), where ...
  7. N

    Geodetic precession and parallel transport

    Could anyone give me a descriptive picture on WHY geodetic precession occurs? I understand the equations from which it follows, so I can derive it algebraically, but I would like to get an intuitive feeling of why it occurs too. My problem is the following: parallel transport of vectors along...
  8. B

    Is Parallel Transport Invariance Maintained in General Relativity Calculations?

    I'm trying to show that \frac{d}{dt}\; g_{\mu \nu} u^{\mu} v^{\nu} = 0 in the context of parallel transport (or maybe not zero), and I'm rather insecure about the procedure. This is akin to problem 3.14 in Hobson's et al. book (General Relativity an introduction for physicists). As a guess, I...
  9. Q

    Physical intuition behind geodesics and parallel transport

    Hi all, Sorry if this is a dumb question, but what exactly do we mean by the term parallel transport? Is it just the physicist's way of saying isometry? Also, in my class we have just defined geodesics, and we're told that having a geodesic curve cis equivalent to demanding that the unit...
  10. D

    Parallel transport and geodesics

    A vector field is parallel transported along a curve if and only if the the corariant derivative of the vector field along the path is 0. That is \frac{d}{d\lambda} V^\mu + \Gamma^\mu_{\sigma \rho} \frac{dx^\sigma}{d\lambda} V^\rho = 0 This is basically what every book says. But what...
  11. W

    Parallel transport analog of Stoke's theorem

    In a Stokes theorem, the integral of all curls of a vector field enclosed in some region is equal to the line integral around the boundary. I'm wondering if a similar theorem exists for parallel transport. The Riemann curvature tensor gives a change in a vector when parallel transported...
  12. M

    Understanding Parallel Transport and its Implications for Coordinate Systems

    I'm a bit confused about parallel transport. We demand that the absolute covariant derivative of our (generalised) coordinates is zero along some curve in some frame. Does this really make our vector stay parallel? What if these coordinates were angles or some other general curvilinear...
  13. O

    Measuring curvature with parallel transport

    Parallel transport, as one means of quantifying the curvature of a coordinate space, enables changes in a vector's components, when it is carried around variously oriented loops in that space, to be properly measured, i.e. by comparisons made at the same location. Those changes which are...
  14. I

    Obtaining the connection from Parallel Transport

    How do I obtain the Levi-Civita connection from the concept of parallel transport? So Do Carmo asks to prove that for vector fields X, Y on M, and for c(t) an integral curve of X, i.e. c(t_0) = p and X(c(t)) = dc/dt, the covariant derivative of Y along X is the derivative of the parallel...
  15. P

    Parallel transport on the sphere

    Homework Statement Consider a closed curve on a sphere. A tangent vector is parallel transported around the curve. Show that the vector is rotated by an angle which is proportional to the solid angle subtended by the area enclosed in the curve. The Attempt at a Solution First, I parametrize...
  16. D

    Parallel transport in flat polar coordinates

    If we have as a manifold euclidian R^2 but expressed in polar coordinates... Do any circle centered at the origin constitute a geodesic? Because I think it parallel transport its own tangent vector.
  17. J

    Parallel transport approximation

    The parallel transport equation is \frac{d\lambda^{\mu}}{d\tau} = -\Gamma^{\mu}_{\sigma\rho} \frac{dx^{\sigma}}{d\tau} \lambda^{\rho} If I take the derivative of this with respect to tau, and get \frac{d^2\lambda^{\mu}}{d\tau^2} =...
  18. S

    Path-ordered product in parallel transport

    I'm reading about bundes and connections but I cannot get past a little problem involving path-ordered exponentials. I hope someone can help me out. I'll try to state the problem as well as possible with plain text LaTeX. My question is just this: How does the the integral (of a general...
  19. J

    Parallel Transport and Triangle Excess Angle

    hi, i am trying to show that the amount by which a vector is rotated by parallel transport around a triangle whose sides are arcs of great circles equals the excess of the sum of the angles over 180 degrees. this is what i have found out so far call the angles of the triangle (assuming...
  20. maddy

    Lie transport vs. parallel transport

    I learned that there exists a difference between Lie transport and parallel transport and what that difference is in differential geometry, but I'm getting all confused again when I read the explanation given in the 'intro to differential forms' thread (below). (posted by jeff) How do we do...
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