Proof of Feynman-Kac theorem












2














I am reading a proof of Feynman-Kac theorem as done here, where I do not follow one step. Specifically, after the author derived:
$$dY_s = u_x(t-s, W_s)e^{-R(s)}dW_s$$
they seem to have concluded $$Y_t =u(0,W_t)e^{-R(t)}$$
in the next line. But the partial derivative in $x$ magically seemed to have disappeared.



Can anyone point out if this is a mistake or this is how it is supposed to be?










share|cite|improve this question



























    2














    I am reading a proof of Feynman-Kac theorem as done here, where I do not follow one step. Specifically, after the author derived:
    $$dY_s = u_x(t-s, W_s)e^{-R(s)}dW_s$$
    they seem to have concluded $$Y_t =u(0,W_t)e^{-R(t)}$$
    in the next line. But the partial derivative in $x$ magically seemed to have disappeared.



    Can anyone point out if this is a mistake or this is how it is supposed to be?










    share|cite|improve this question

























      2












      2








      2







      I am reading a proof of Feynman-Kac theorem as done here, where I do not follow one step. Specifically, after the author derived:
      $$dY_s = u_x(t-s, W_s)e^{-R(s)}dW_s$$
      they seem to have concluded $$Y_t =u(0,W_t)e^{-R(t)}$$
      in the next line. But the partial derivative in $x$ magically seemed to have disappeared.



      Can anyone point out if this is a mistake or this is how it is supposed to be?










      share|cite|improve this question













      I am reading a proof of Feynman-Kac theorem as done here, where I do not follow one step. Specifically, after the author derived:
      $$dY_s = u_x(t-s, W_s)e^{-R(s)}dW_s$$
      they seem to have concluded $$Y_t =u(0,W_t)e^{-R(t)}$$
      in the next line. But the partial derivative in $x$ magically seemed to have disappeared.



      Can anyone point out if this is a mistake or this is how it is supposed to be?







      probability-theory stochastic-processes brownian-motion






      share|cite|improve this question













      share|cite|improve this question











      share|cite|improve this question




      share|cite|improve this question










      asked Nov 27 '18 at 1:41









      dezdichado

      6,1781929




      6,1781929






















          1 Answer
          1






          active

          oldest

          votes


















          0














          It's a lot simpler than you thought. The definition of $Y_s$ is given in the beginning of the proof. He doesn't use the expression for $dY_s$ in any way in writing down $Y_t$.



          At the beginning he defines $Y_s=e^{-R(s)}u(t-s,W_s)$. Letting $s=t$ gives $Y_t=e^{-R(t)}u(0,W_t)$.






          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%2f3015207%2fproof-of-feynman-kac-theorem%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









            0














            It's a lot simpler than you thought. The definition of $Y_s$ is given in the beginning of the proof. He doesn't use the expression for $dY_s$ in any way in writing down $Y_t$.



            At the beginning he defines $Y_s=e^{-R(s)}u(t-s,W_s)$. Letting $s=t$ gives $Y_t=e^{-R(t)}u(0,W_t)$.






            share|cite|improve this answer


























              0














              It's a lot simpler than you thought. The definition of $Y_s$ is given in the beginning of the proof. He doesn't use the expression for $dY_s$ in any way in writing down $Y_t$.



              At the beginning he defines $Y_s=e^{-R(s)}u(t-s,W_s)$. Letting $s=t$ gives $Y_t=e^{-R(t)}u(0,W_t)$.






              share|cite|improve this answer
























                0












                0








                0






                It's a lot simpler than you thought. The definition of $Y_s$ is given in the beginning of the proof. He doesn't use the expression for $dY_s$ in any way in writing down $Y_t$.



                At the beginning he defines $Y_s=e^{-R(s)}u(t-s,W_s)$. Letting $s=t$ gives $Y_t=e^{-R(t)}u(0,W_t)$.






                share|cite|improve this answer












                It's a lot simpler than you thought. The definition of $Y_s$ is given in the beginning of the proof. He doesn't use the expression for $dY_s$ in any way in writing down $Y_t$.



                At the beginning he defines $Y_s=e^{-R(s)}u(t-s,W_s)$. Letting $s=t$ gives $Y_t=e^{-R(t)}u(0,W_t)$.







                share|cite|improve this answer












                share|cite|improve this answer



                share|cite|improve this answer










                answered Nov 27 '18 at 5:16









                Zachary Selk

                579311




                579311






























                    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%2f3015207%2fproof-of-feynman-kac-theorem%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

                    Quarter-circle Tiles

                    build a pushdown automaton that recognizes the reverse language of a given pushdown automaton?

                    Mont Emei