Exponential map on the Fisher manifold for exponential family distribution












0














So, I don't really understand too well Diff. Geometry and Manifolds currently. Hence, I've started studying it and it is very interesting. However, atm I just need to understand how to compute the exponential map for the Fisher manifold of exponential family distributions. Unfortunately, this is a timely manner so I'm afaraid I will need to do this before I actually learn it properly following my study.



Essentially, I'm interested in understanding given that we have a predefined Riemannian metric tensor (in this case the Fisher matrix), as I understand the exponential map will give me given a tangent vector a point $p$ the unique geodesic that is in the same direction as the tangent vector at unit speed. To me this suggest that one should be able to setup this as an optimization problem, whose solution (if anayltically exists) defines the exponential map. However, for some reason I don't seem to be able to derive this accordingly.



For instance consider a Gaussian distribution with fixed mean 0 and a covariance matrix $Sigma$. Consider the Fisher Manifold with respect to the covariance. The Fisher matrix is
$$frac{Sigma^{-1} otimes Sigma^{-1}}{2}$$
Given this information what is the actual mathematical problem that one needs to setup in order to arrive at (taken from http://www.dima.unige.it/~riccomag/Pistone-2017-01-23.pdf):
$$
Exp(tM;Sigma) = Sigma^{frac{1}{2}} exp left[Sigma^{-frac{1}{2}} (tV) Sigma^{-frac{1}{2}} right] Sigma^{frac{1}{2}}
$$










share|cite|improve this question



























    0














    So, I don't really understand too well Diff. Geometry and Manifolds currently. Hence, I've started studying it and it is very interesting. However, atm I just need to understand how to compute the exponential map for the Fisher manifold of exponential family distributions. Unfortunately, this is a timely manner so I'm afaraid I will need to do this before I actually learn it properly following my study.



    Essentially, I'm interested in understanding given that we have a predefined Riemannian metric tensor (in this case the Fisher matrix), as I understand the exponential map will give me given a tangent vector a point $p$ the unique geodesic that is in the same direction as the tangent vector at unit speed. To me this suggest that one should be able to setup this as an optimization problem, whose solution (if anayltically exists) defines the exponential map. However, for some reason I don't seem to be able to derive this accordingly.



    For instance consider a Gaussian distribution with fixed mean 0 and a covariance matrix $Sigma$. Consider the Fisher Manifold with respect to the covariance. The Fisher matrix is
    $$frac{Sigma^{-1} otimes Sigma^{-1}}{2}$$
    Given this information what is the actual mathematical problem that one needs to setup in order to arrive at (taken from http://www.dima.unige.it/~riccomag/Pistone-2017-01-23.pdf):
    $$
    Exp(tM;Sigma) = Sigma^{frac{1}{2}} exp left[Sigma^{-frac{1}{2}} (tV) Sigma^{-frac{1}{2}} right] Sigma^{frac{1}{2}}
    $$










    share|cite|improve this question

























      0












      0








      0







      So, I don't really understand too well Diff. Geometry and Manifolds currently. Hence, I've started studying it and it is very interesting. However, atm I just need to understand how to compute the exponential map for the Fisher manifold of exponential family distributions. Unfortunately, this is a timely manner so I'm afaraid I will need to do this before I actually learn it properly following my study.



      Essentially, I'm interested in understanding given that we have a predefined Riemannian metric tensor (in this case the Fisher matrix), as I understand the exponential map will give me given a tangent vector a point $p$ the unique geodesic that is in the same direction as the tangent vector at unit speed. To me this suggest that one should be able to setup this as an optimization problem, whose solution (if anayltically exists) defines the exponential map. However, for some reason I don't seem to be able to derive this accordingly.



      For instance consider a Gaussian distribution with fixed mean 0 and a covariance matrix $Sigma$. Consider the Fisher Manifold with respect to the covariance. The Fisher matrix is
      $$frac{Sigma^{-1} otimes Sigma^{-1}}{2}$$
      Given this information what is the actual mathematical problem that one needs to setup in order to arrive at (taken from http://www.dima.unige.it/~riccomag/Pistone-2017-01-23.pdf):
      $$
      Exp(tM;Sigma) = Sigma^{frac{1}{2}} exp left[Sigma^{-frac{1}{2}} (tV) Sigma^{-frac{1}{2}} right] Sigma^{frac{1}{2}}
      $$










      share|cite|improve this question













      So, I don't really understand too well Diff. Geometry and Manifolds currently. Hence, I've started studying it and it is very interesting. However, atm I just need to understand how to compute the exponential map for the Fisher manifold of exponential family distributions. Unfortunately, this is a timely manner so I'm afaraid I will need to do this before I actually learn it properly following my study.



      Essentially, I'm interested in understanding given that we have a predefined Riemannian metric tensor (in this case the Fisher matrix), as I understand the exponential map will give me given a tangent vector a point $p$ the unique geodesic that is in the same direction as the tangent vector at unit speed. To me this suggest that one should be able to setup this as an optimization problem, whose solution (if anayltically exists) defines the exponential map. However, for some reason I don't seem to be able to derive this accordingly.



      For instance consider a Gaussian distribution with fixed mean 0 and a covariance matrix $Sigma$. Consider the Fisher Manifold with respect to the covariance. The Fisher matrix is
      $$frac{Sigma^{-1} otimes Sigma^{-1}}{2}$$
      Given this information what is the actual mathematical problem that one needs to setup in order to arrive at (taken from http://www.dima.unige.it/~riccomag/Pistone-2017-01-23.pdf):
      $$
      Exp(tM;Sigma) = Sigma^{frac{1}{2}} exp left[Sigma^{-frac{1}{2}} (tV) Sigma^{-frac{1}{2}} right] Sigma^{frac{1}{2}}
      $$







      manifolds riemannian-geometry fisher-information information-geometry






      share|cite|improve this question













      share|cite|improve this question











      share|cite|improve this question




      share|cite|improve this question










      asked Nov 21 '18 at 20:06









      Alex BotevAlex Botev

      674314




      674314






















          1 Answer
          1






          active

          oldest

          votes


















          1














          "Geodesic shooting" method for computating gesodesic distance between 2 multivariate densities of different means aand different covariance matrices:
          https://ieeexplore.ieee.org/abstract/document/7497346






          share|cite|improve this answer





















            Your Answer





            StackExchange.ifUsing("editor", function () {
            return StackExchange.using("mathjaxEditing", function () {
            StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
            StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
            });
            });
            }, "mathjax-editing");

            StackExchange.ready(function() {
            var channelOptions = {
            tags: "".split(" "),
            id: "69"
            };
            initTagRenderer("".split(" "), "".split(" "), channelOptions);

            StackExchange.using("externalEditor", function() {
            // Have to fire editor after snippets, if snippets enabled
            if (StackExchange.settings.snippets.snippetsEnabled) {
            StackExchange.using("snippets", function() {
            createEditor();
            });
            }
            else {
            createEditor();
            }
            });

            function createEditor() {
            StackExchange.prepareEditor({
            heartbeatType: 'answer',
            autoActivateHeartbeat: false,
            convertImagesToLinks: true,
            noModals: true,
            showLowRepImageUploadWarning: true,
            reputationToPostImages: 10,
            bindNavPrevention: true,
            postfix: "",
            imageUploader: {
            brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
            contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
            allowUrls: true
            },
            noCode: true, onDemand: true,
            discardSelector: ".discard-answer"
            ,immediatelyShowMarkdownHelp:true
            });


            }
            });














            draft saved

            draft discarded


















            StackExchange.ready(
            function () {
            StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3008277%2fexponential-map-on-the-fisher-manifold-for-exponential-family-distribution%23new-answer', 'question_page');
            }
            );

            Post as a guest















            Required, but never shown

























            1 Answer
            1






            active

            oldest

            votes








            1 Answer
            1






            active

            oldest

            votes









            active

            oldest

            votes






            active

            oldest

            votes









            1














            "Geodesic shooting" method for computating gesodesic distance between 2 multivariate densities of different means aand different covariance matrices:
            https://ieeexplore.ieee.org/abstract/document/7497346






            share|cite|improve this answer


























              1














              "Geodesic shooting" method for computating gesodesic distance between 2 multivariate densities of different means aand different covariance matrices:
              https://ieeexplore.ieee.org/abstract/document/7497346






              share|cite|improve this answer
























                1












                1








                1






                "Geodesic shooting" method for computating gesodesic distance between 2 multivariate densities of different means aand different covariance matrices:
                https://ieeexplore.ieee.org/abstract/document/7497346






                share|cite|improve this answer












                "Geodesic shooting" method for computating gesodesic distance between 2 multivariate densities of different means aand different covariance matrices:
                https://ieeexplore.ieee.org/abstract/document/7497346







                share|cite|improve this answer












                share|cite|improve this answer



                share|cite|improve this answer










                answered Nov 22 '18 at 20:22









                Frederic BarbarescoFrederic Barbaresco

                362




                362






























                    draft saved

                    draft discarded




















































                    Thanks for contributing an answer to Mathematics Stack Exchange!


                    • Please be sure to answer the question. Provide details and share your research!

                    But avoid



                    • Asking for help, clarification, or responding to other answers.

                    • Making statements based on opinion; back them up with references or personal experience.


                    Use MathJax to format equations. MathJax reference.


                    To learn more, see our tips on writing great answers.





                    Some of your past answers have not been well-received, and you're in danger of being blocked from answering.


                    Please pay close attention to the following guidance:


                    • Please be sure to answer the question. Provide details and share your research!

                    But avoid



                    • Asking for help, clarification, or responding to other answers.

                    • Making statements based on opinion; back them up with references or personal experience.


                    To learn more, see our tips on writing great answers.




                    draft saved


                    draft discarded














                    StackExchange.ready(
                    function () {
                    StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3008277%2fexponential-map-on-the-fisher-manifold-for-exponential-family-distribution%23new-answer', 'question_page');
                    }
                    );

                    Post as a guest















                    Required, but never shown





















































                    Required, but never shown














                    Required, but never shown












                    Required, but never shown







                    Required, but never shown

































                    Required, but never shown














                    Required, but never shown












                    Required, but never shown







                    Required, but never shown







                    Popular posts from this blog

                    Can a sorcerer learn a 5th-level spell early by creating spell slots using the Font of Magic feature?

                    ts Property 'filter' does not exist on type '{}'

                    mat-slide-toggle shouldn't change it's state when I click cancel in confirmation window