What is Poincare: Definition and 154 Discussions

Poincaré is a French surname. Notable people with the surname include:

Henri Poincaré (1854–1912), physicist, mathematician and philosopher of science
Henriette Poincaré (1858-1943), wife of Prime Minister Raymond Poincaré
Lucien Poincaré (1862–1920), physicist, brother of Raymond and cousin of Henri
Raymond Poincaré (1860–1934), French Prime Minister or President inter alia from 1913 to 1920, cousin of Henri

View More On Wikipedia.org
Recent contents Top users
  1. M

    Poincaré Gauge Theory: Facts, Popularity, Flaws & Experiments

    Does someone know something about this theory? Is it popular, or just accepted by very few people? What is the flaw or defect of this theory? Has it been ruled out by some observations or experiments? Thx.
  2. P

    Are Lorentz and Poincare insufficiently credited for special relativity?

    Einstein is commonly regarded as the primary inventor of special relativity. I'd like to trust the collective wisdom of others, but I never feel fully convinced. The argument is typically "Though people like Lorentz and Poincare have worked out most of the math it's only Einstein who realized...
  3. tom.stoer

    Representations of the Poincare group

    Hello, in relativistic quantum field theories all particles are members of (unitary) representations of the Poincare group. For massive particles m² > 0 one gets the usual scalar / spinor / vector representations with spin J = 0, 1/2, 1, 3/2, ... and dim. rep. = 2J+1. For massless particles...
  4. maverick280857

    Galilean Algebra in the low velocity limit of Poincare Algebra (Weinberg vol 1)

    Hi, Can someone please explain the following statement on page 62 of Weinberg's Vol 1 on QFT: (I understand the part for P ~ mv, so the "quote" is slightly distorted, intentionally). Also how is ? Thanks in advance!
  5. M

    Poincare Conjecture: Understanding & Appreciating the Proof

    hello! i would like to be able to understand and appreciate the proof of the poincare conjecture. i have some idea of where to begin, and my supervisor is going to help me out (i'm starting a master's in pure math and my supervisor does geometric analysis), but i was wondering if anyone here...
  6. J

    Is Local Poincare Symmetry Exact in All Approaches to Quantum Gravity?

    It is my understanding that in string theory, loop quantum gravity, the 'asymptotic safety' approach, and in semiclassical quantum gravity, local Poincare symmetry is exact. But there are things like DSR (does the D stand for Deformed, or Doubly? I've heard people say it either way), which...
  7. Rasalhague

    What Is the Euclidean Analog of the Poincaré Group?

    Benjamin Crowell writes here, "The discontinuous transformations of spatial reflection and time reversal are not included in the definition of the Poincaré group, although they do preserve inner products." http://www.lightandmatter.com/html_books/genrel/ch02/ch02.html So, if I've...
  8. N

    Solve 0=u''+u*e^x | Poincare Return Map

    How do I write u''+u*e^x = 0 as a planar system?
  9. H

    Exploring the Poincaré Disc: Understanding Infinity

    hi there What is a Poincare' disc and why is the edges of disc represent infinity? thanks
  10. A

    Is poincare group simply connected?

    (I posted this in Particle Physics too) We call a group G "simply connected" if every curve C(t) in G which is closed (that is, C(0) = C(1) = I) can be continuously deformed into the trivial curve C'(t) = I (where I is the unit element in G). This is formalised saying that, for each closed...
  11. A

    Is poincare grouo simply connected?

    We call a group G "simply connected" if every curve C(t) in G which is closed (that is, C(0) = C(1) = I) can be continuously deformed into the trivial curve C'(t) = I (where I is the unit element in G). This is formalised saying that, for each closed C(t), there exists a continuous function F...
  12. C

    Poincare conserved currents : Energy-momentum and Angular-momentum tensors

    Not sure if this is the right place to ask, but this doubt originated when reading on string theory and so here it goes... The general canonical energy-momentum tensor (as derived from translation invariance), T^{\mu\nu}_{C} is not symmetric. Also, the general angular momentum conserved...
  13. X

    Lorentz or Poincare invariant?

    Generally we say GR is local Lorentz invariant. Does it mean the action or field equation? Why not Poincare invariant? Thanks!
  14. M

    Poincare sphere and Degree of polarization

    Hi, Can someone explain the concept of "Poincare sphere"? What's the relationship between the Poincare Sphere and the Degree of polarization of EM fields? Thanks Madara
  15. B

    Matrix reppresentation of poincare group generators

    Does anyone know what a matrix representation of the poincare group generators looks like (specifically the translation parts)? I've been trying to figure this out but I get matrices that are dependent on the group parameters.
  16. N

    Massless representations of the Poincare group

    Never mind, I answered my own question...
  17. N

    Understanding the Dilemma: Differential Operators and the Poincare Algebra

    I am facing a dilemma which leaves me quite puzzled. I hope someone can straighten this out. The short version is : when we use representations of the charges as differential operators to calculate their commutators, we always get -1 times the correct result. So, doe sthat mean that we...
  18. M

    Prove: Poincare Model I-1 Holes for Every Two Points of E

    Incidence Postualte I-1 holes for the Poincare Model: Every two points of E lie on exactly one L-Line. Prove: Given any two points P and Q inside the unit circle C, there exists a unique L-line l containing them. (this will require the use of analytic geometry.) L-lines:arcs of circles...
  19. P

    Deriving the Poincare algebra in scalar field theory

    Homework Statement Find the commutators [P^\sigma,J^{\mu \nu}] The answer is part of the Poincare algebra [P^\sigma,J^{\mu \nu}]=i(g^{\mu \sigma}P^\nu-g^{\nu \sigma}P^\mu) If someone can convince me that \partial_i T^{0\mu} = 0, (i.e. the energy-momentum tensor has no explicit spatial...
  20. H

    Poincaré on the constancy of light

    It's notable that Poincaré many years before Einstein had very interesting ideas on the constancy of light. For example: In his paper http://en.wikisource.org/wiki/The_Measure_of_Time" Poincaré wrote in 1898: Abraham Pais (in Subtle is the Lord) said that "These lines read like the general...
  21. H

    Theorems of Liouville and Poincare & their relation to entropy

    If we have a system for which the Liouville's tm holds, can we automaticly say the Poincare's recurrence tm also holds? Presumably this is true in microcanonical ansable, but how about canonical, where the energy isn't constant?
  22. B

    Why Are Two Indices Used for the Generators of Lorentz and Poincare Groups?

    Just a quick question here: I was going through my notes and I noticed that the generators of both these groups are labeled two indices. I was wondering if there is any particular reason for this, since it seems to me that one index would work perfectly well. Thanks
  23. U

    QFT: Find Poincare Group Generators in QFT

    Hi I need to find the generators of the Poincare group in the representation of a clasical scalar field. Every textbook I found let them as P and M. But any buk does not what are they. I'm wondering if anybody help me to find this Uda
  24. T

    Perturbation Theory - Poincare Method

    Hello, I have some trouble while trying to use the Poincare method in a free fall problem. There's some point on earth, that the vector R0 points at. from this point there is an orthonormal coordinate system, and some point of mass at (Rx, Ry, Rz). I found the expression for the sum of...
  25. P

    Poincare section and bifurcation diagram

    Homework Statement This is the bouncing ball experiment, a circuit is used as an analog of a ball bouncing on an oscillating table. The amplitude of the tables oscillations is varied and data representing the balls position and velocity is gathered. I have to plot a poincare section for...
  26. E

    Solved Poincaré Conjecture: Find Perelman's Proof Here

    [SOLVED] poincare conjecture http://en.wikipedia.org/wiki/Solution_of_the_Poincar%C3%A9_conjecture The links to Perelman's original proof do not work. Can someone fix them please?
  27. vincentm

    Solving of the Poincare' Conjecture

    Ok first i'd like to note that I'm not good at mathematics and have a vague understanding of the conjecture. What i'd like to know though is what comes now that this has been solved by Perelman? What implications does this have?
  28. P

    Poincare Conjecture: Fundamental Group of V Explained

    Does the Poincare conjecture say: Consider a compact 3-dimensional manifold V without boundary. Poincare conjectured that The fundamental group of V is trivial => V is homeomorphic to the 3-dimensional sphere? It has been proved for all manifolds except 3. However Perelman completed a proof...
  29. G

    Dynamical systems: celestial mechanics, Poincare, Laplace, butterfly effect

    There is a work in history of astronomy I've been preparing for the most of the time in living memory. I can't say is it late, or due, or long, but counting from the 3 books I've seen, the one in focus of some private interest is Michael Hoskin "Cambridge Illustrated History of Astronomy"...
  30. K

    Poincaré conjecture - singularities - quantum cohomology

    In 2006, the mathematically rigorous proof of the Poincaré conjecture was completely excepted. The Poincaré conjecture was put forward by Henri Poincaré in the early 1900's. It is a theorem about the characterization of the 3D sphere amongst 3D manifolds. It was considered one of the most...
  31. K

    Impact of Poincaré conjecture on mathematics?

    In 2006, the mathematically rigorous proof of the Poincaré conjecture was completely excepted. The Poincaré conjecture was put forward by Henri Poincaré in the early 1900's. It is a theorem about the characterization of the 3D sphere amongst 3D manifolds. It was considered one of the most...
  32. P

    Find Poincare Transform for Momentarily Co-Moving Reference Frame

    After a lot of searching I cannot for the life of me find the transformation for a Momentarily Co-moving Reference Frame. Essentially what I'm looking for is the transformations from inertial frame Sigma to inertial frame Sigma[']. Sigma['] is moving at speed v relative to Sigma not along any...
  33. A

    Exploring Supersymmetry Breaking & Poincare Invariance

    I recently studied supersymmetry breaking and read there that for Supersymmetry breaking we have the energy of the vacuum state >0. However what I do not really see is why such a vacuum would not break Poincare invariance as well as the energy is part of the momentum 4-vector and so transforms...
  34. L

    Lorentz group, Poincaré group and conformal group

    Dear all, I just received by mail the https://www.amazon.com/dp/0471925675/?tag=pfamazon01-20. I am very very happy. At each page I can see something new to learn. But I would like to learn a bit more about his remark on page 28. (you can read it with the amazon reader) He talks about...
  35. R

    Poincare Conjecture Explained: Layman's Terms

    What is the poincare conjecture in layman's terms?
  36. N

    Navier&Stokes to follow Poincare?

    Navier&Stokes to follow Poincare?? It seems that yet another important problem in mathematics, and more importantly in physics, may have been solved. This time it's the Navier-Stokes Equation. This, too, is on the Clay Mathematical Institute's list of Millenium Problems. I've seen a couple of...
  37. M

    Can the Poincare Conjecture Simplify 3D Objects for Mathematical Calculations?

    After reading the article on Poincare's conjecture in the Economist, I became curious about simplified 3-dimensional objects. Excerpt: Let's take a cube and simplify it into a circle. Could we then use equations ment for circles for the simplified shape, ie calculate the cube's surface...
  38. CarlB

    Poincare Invariance from General QFT

    Derivation of Poincare Invariance from general quantum field theory C.D. Froggatt, H.B. Nielsen Annalen der Physik, Volume 14, Issue 1-3 , Pages 115 - 147 (2005) Special Issue commemorating Albert Einstein Starting from a very general quantum field theory we seek to derive Poincare...
  39. N

    Proof of Poincare Recurrence Theorem

    Does anyone know of an accessible reference that sketches a proof of Poincare's recurrence theorem? (This is not a homework question.) I'm coming up short in my searches -- either the proof is too sketchy, or it is inaccessible to me (little background in maths, but enough to talk about...
  40. Clausius2

    Perelman, Poincare Conjecture solved now?

    Perelman, Poincare Conjecture solved now?? Seems that this guy has solved the Poincaré Conjecture: http://en.wikipedia.org/wiki/Grigori_Perelman He is supposed to get the Fields Medal in Madrid this year, in the next international congress of mathematics. But it is likely that he won't...
  41. S

    Complete Solution of Poincare Conjecture

    Announced in http://www.intlpress.com/AJM/p/2006/10_2/AJM-10-2-165-492.pdf" . Differential Geometry meets Geometric Surgery on three-manifolds; Perelman clarified and (perhaps) corrected. A COMPLETE PROOF OF THE POINCAR´E AND GEOMETRIZATION CONJECTURES – APPLICATION OF THE...
  42. P

    Numerical Analysis - Construction of a Poincare surface of section

    (I am not sure whether I'm posting in the right forum. I apologize if I do) Does anyone have an alrorithm or a code (in any language) that constructs a Poincare surface of section? I want to do so for a Hamiltonian model: A mass under the influense of the Henon-Heiles potential. It has to...
  43. N

    Poincare Recurrence and the Infinite N Limit

    (One version of) Poincare's Recurrence Theorem states that for any conservative system whose possible states S form a compact set in phase space, that system will "almost always" return arbitrarily close to its initial state, provided we wait long enough. ('Almost always' means 'all but a set...
  44. A

    Poincaré invariant action of a point particle

    I am an MPhys graduate currently reading Joseph Polchinski’s, String Theory, Vol. 1. Unsurprisingly I’m stuck on the first real bit of maths… :p I quote from page 10, heh: “The simplest Poincaré invariant action that does not depend on the parametrization would be proportional to the proper...
  45. A

    Poincare invariant action of a point particle

    I am an MPhys graduate currently reading Joseph Polchinski’s, String Theory, Vol. 1. Unsurprisingly I’m stuck on the first real bit of maths… :p I quote from page 10, heh: “The simplest Poincaré invariant action that does not depend on the parametrization would be proportional to the proper...
  46. R

    Understanding the Poincare Conjecture: A Layman's Guide

    Could someone lay down, in layman's terms, The Poincare Conjecture? Lol, is this even possible?
  47. P

    Henri Poincaré: The Real Discoverer of Special Relativity

    Why isn't the mathematician Henri Poincaré acknowledged as the true discoverer of special relativity? http://www-cosmosaf.iap.fr/Poincare-RR3A.htm http://arxiv.org/abs/physics/0408077
  48. kakarukeys

    Question on Poincare Recurrence Theorem

    Poincare Recurrence Theorem states that: "If a flow preserves volume and has only bounded orbits then for each open set there exist orbits that intersect the set infinitely often." But it does not imply (does it?) that "In hamiltonian system with bounded phase space, all trajectories will...
  49. I

    Has the Poincaré Conjecture Been Proven? A Review of the Proposed Proof

    http://mathworld.wolfram.com/news/2003-04-15/poincare/ Is the proof considered valid? Did he claim the millennium prize? I can't find any recent news about it.
  50. C

    A Naive String Theory Question on 10 Dimensions and Poincare Transformation

    I do not know much about string theory, but the fact that it involves 10 or 11 dimensions. I am curious whether this 10 or 11 dimensions of string theory has anything to do with inhomogenous lorentz transformation?. ---- [from Goldstein - section 7-2] In essence a poincare...
Back
Top