enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Morse theory - Wikipedia

    en.wikipedia.org/wiki/Morse_theory

    A less trivial example of a degenerate critical point is the origin of the monkey saddle. The index of a non-degenerate critical point of is the dimension of the largest subspace of the tangent space to at on which the Hessian is negative definite.

  3. Critical point (mathematics) - Wikipedia

    en.wikipedia.org/wiki/Critical_point_(mathematics)

    For a function of n variables, the number of negative eigenvalues of the Hessian matrix at a critical point is called the index of the critical point. A non-degenerate critical point is a local maximum if and only if the index is n, or, equivalently, if the Hessian matrix is negative definite; it is a local minimum if the index is zero, or ...

  4. Hessian matrix - Wikipedia

    en.wikipedia.org/wiki/Hessian_matrix

    Otherwise it is non-degenerate, and called a Morse critical point of . The Hessian matrix plays an important role in Morse theory and catastrophe theory, because its kernel and eigenvalues allow classification of the critical points. [2] [3] [4]

  5. Stationary phase approximation - Wikipedia

    en.wikipedia.org/wiki/Stationary_phase_approximation

    The second statement is that when f is a Morse function, so that the singular points of f are non-degenerate and isolated, then the question can be reduced to the case n = 1. In fact, then, a choice of g can be made to split the integral into cases with just one critical point P in each.

  6. Critical phenomena - Wikipedia

    en.wikipedia.org/wiki/Critical_phenomena

    The critical point is described by a conformal field theory. According to the renormalization group theory, the defining property of criticality is that the characteristic length scale of the structure of the physical system, also known as the correlation length ξ, becomes infinite. This can happen along critical lines in phase space.

  7. Berry connection and curvature - Wikipedia

    en.wikipedia.org/wiki/Berry_connection_and_curvature

    If the 'th eigenvalue remains non-degenerate everywhere along the path and the variation with time t is sufficiently slow, then a system initially in the normalized eigenstate | (()) will remain in an instantaneous eigenstate | (()) of the Hamiltonian (()), up to a phase, throughout the process.

  8. Method of steepest descent - Wikipedia

    en.wikipedia.org/wiki/Method_of_steepest_descent

    when λ → ∞, f (x) is continuous, and S(z) has a degenerate saddle point, is a very rich problem, whose solution heavily relies on the catastrophe theory. Here, the catastrophe theory replaces the Morse lemma, valid only in the non-degenerate case, to transform the function S(z) into one of

  9. Milnor number - Wikipedia

    en.wikipedia.org/wiki/Milnor_number

    It is assumed that f has a degenerate singularity at 0. The multiplicity of this degenerate singularity may be considered by thinking about how many points are infinitesimally glued. If the image of f is now perturbed in a certain stable way the isolated degenerate singularity at 0 will split up into other isolated singularities which are non ...