{"title":"用Clark-Ocone公式表示布朗运动的局部时间","authors":"Allaoui Omar , Hadiri Sokaina , Sghir Aissa","doi":"10.1016/j.rinam.2025.100563","DOIUrl":null,"url":null,"abstract":"<div><div>Let <span><math><mrow><mo>(</mo><mrow><msup><mrow><mi>L</mi></mrow><mrow><mi>B</mi></mrow></msup><mrow><mo>(</mo><mi>t</mi><mo>,</mo><mi>x</mi><mo>)</mo></mrow><mo>,</mo><mspace></mspace><mi>t</mi><mo>≥</mo><mn>0</mn><mo>,</mo><mspace></mspace><mi>x</mi><mo>∈</mo><mi>R</mi></mrow><mo>)</mo></mrow></math></span> be the local time of <span><math><mrow><mrow><mo>(</mo><mrow><msub><mrow><mi>B</mi></mrow><mrow><mi>t</mi></mrow></msub><mo>,</mo><mspace></mspace><mi>t</mi><mo>≥</mo><mn>0</mn></mrow><mo>)</mo></mrow><mo>,</mo></mrow></math></span> the real-valued one-dimensional Brownian motion. In this paper, in case of <span><math><mrow><mi>g</mi><mo>,</mo></mrow></math></span> a strictly increasing and bijective function, we propose some integral representations of <span><math><mrow><msup><mrow><mi>L</mi></mrow><mrow><mi>g</mi><mrow><mo>(</mo><mi>B</mi><mo>)</mo></mrow></mrow></msup><mrow><mo>(</mo><mi>t</mi><mo>,</mo><mi>x</mi><mo>)</mo></mrow><mo>,</mo></mrow></math></span> of the form: <span><math><mrow><mi>R</mi><mrow><mo>(</mo><mi>t</mi><mo>,</mo><mi>x</mi><mo>)</mo></mrow><mo>+</mo><msubsup><mrow><mo>∫</mo></mrow><mrow><mn>0</mn></mrow><mrow><mi>t</mi></mrow></msubsup><mi>K</mi><mrow><mo>(</mo><mi>t</mi><mo>,</mo><mi>x</mi><mo>,</mo><msub><mrow><mi>B</mi></mrow><mrow><mi>s</mi></mrow></msub><mo>)</mo></mrow><mi>d</mi><msub><mrow><mi>B</mi></mrow><mrow><mi>s</mi></mrow></msub><mo>,</mo></mrow></math></span> where <span><math><mrow><mi>R</mi><mrow><mo>(</mo><mi>t</mi><mo>,</mo><mi>x</mi><mo>)</mo></mrow></mrow></math></span> is a deterministic function and <span><math><mrow><mi>K</mi><mrow><mo>(</mo><mi>t</mi><mo>,</mo><mi>x</mi><mo>,</mo><msub><mrow><mi>B</mi></mrow><mrow><mi>s</mi></mrow></msub><mo>)</mo></mrow></mrow></math></span> is a random function depending on <span><math><mi>t</mi></math></span> and <span><math><mrow><mi>F</mi><mo>,</mo></mrow></math></span> the cumulative distribution function of the standard normal distribution <span><math><mrow><mi>N</mi><mrow><mo>(</mo><mn>0</mn><mo>,</mo><mn>1</mn><mo>)</mo></mrow></mrow></math></span> and some Brownian functionals with no Malliavin derivative. Our study is based on the case <span><math><mrow><msup><mrow><mi>L</mi></mrow><mrow><mi>B</mi></mrow></msup><mrow><mo>(</mo><mi>t</mi><mo>,</mo><mi>x</mi><mo>)</mo></mrow><mo>.</mo></mrow></math></span> An exact formula of the expectation <span><math><mrow><mi>E</mi><mrow><mo>[</mo><mrow><msup><mrow><mi>L</mi></mrow><mrow><mi>B</mi></mrow></msup><mrow><mo>(</mo><mi>t</mi><mo>,</mo><mi>x</mi><mo>)</mo></mrow></mrow><mo>]</mo></mrow></mrow></math></span> is given in this paper.</div></div>","PeriodicalId":36918,"journal":{"name":"Results in Applied Mathematics","volume":"26 ","pages":"Article 100563"},"PeriodicalIF":1.4000,"publicationDate":"2025-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"An integral representation of the local time of the Brownian motion via the Clark–Ocone formula\",\"authors\":\"Allaoui Omar , Hadiri Sokaina , Sghir Aissa\",\"doi\":\"10.1016/j.rinam.2025.100563\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>Let <span><math><mrow><mo>(</mo><mrow><msup><mrow><mi>L</mi></mrow><mrow><mi>B</mi></mrow></msup><mrow><mo>(</mo><mi>t</mi><mo>,</mo><mi>x</mi><mo>)</mo></mrow><mo>,</mo><mspace></mspace><mi>t</mi><mo>≥</mo><mn>0</mn><mo>,</mo><mspace></mspace><mi>x</mi><mo>∈</mo><mi>R</mi></mrow><mo>)</mo></mrow></math></span> be the local time of <span><math><mrow><mrow><mo>(</mo><mrow><msub><mrow><mi>B</mi></mrow><mrow><mi>t</mi></mrow></msub><mo>,</mo><mspace></mspace><mi>t</mi><mo>≥</mo><mn>0</mn></mrow><mo>)</mo></mrow><mo>,</mo></mrow></math></span> the real-valued one-dimensional Brownian motion. In this paper, in case of <span><math><mrow><mi>g</mi><mo>,</mo></mrow></math></span> a strictly increasing and bijective function, we propose some integral representations of <span><math><mrow><msup><mrow><mi>L</mi></mrow><mrow><mi>g</mi><mrow><mo>(</mo><mi>B</mi><mo>)</mo></mrow></mrow></msup><mrow><mo>(</mo><mi>t</mi><mo>,</mo><mi>x</mi><mo>)</mo></mrow><mo>,</mo></mrow></math></span> of the form: <span><math><mrow><mi>R</mi><mrow><mo>(</mo><mi>t</mi><mo>,</mo><mi>x</mi><mo>)</mo></mrow><mo>+</mo><msubsup><mrow><mo>∫</mo></mrow><mrow><mn>0</mn></mrow><mrow><mi>t</mi></mrow></msubsup><mi>K</mi><mrow><mo>(</mo><mi>t</mi><mo>,</mo><mi>x</mi><mo>,</mo><msub><mrow><mi>B</mi></mrow><mrow><mi>s</mi></mrow></msub><mo>)</mo></mrow><mi>d</mi><msub><mrow><mi>B</mi></mrow><mrow><mi>s</mi></mrow></msub><mo>,</mo></mrow></math></span> where <span><math><mrow><mi>R</mi><mrow><mo>(</mo><mi>t</mi><mo>,</mo><mi>x</mi><mo>)</mo></mrow></mrow></math></span> is a deterministic function and <span><math><mrow><mi>K</mi><mrow><mo>(</mo><mi>t</mi><mo>,</mo><mi>x</mi><mo>,</mo><msub><mrow><mi>B</mi></mrow><mrow><mi>s</mi></mrow></msub><mo>)</mo></mrow></mrow></math></span> is a random function depending on <span><math><mi>t</mi></math></span> and <span><math><mrow><mi>F</mi><mo>,</mo></mrow></math></span> the cumulative distribution function of the standard normal distribution <span><math><mrow><mi>N</mi><mrow><mo>(</mo><mn>0</mn><mo>,</mo><mn>1</mn><mo>)</mo></mrow></mrow></math></span> and some Brownian functionals with no Malliavin derivative. Our study is based on the case <span><math><mrow><msup><mrow><mi>L</mi></mrow><mrow><mi>B</mi></mrow></msup><mrow><mo>(</mo><mi>t</mi><mo>,</mo><mi>x</mi><mo>)</mo></mrow><mo>.</mo></mrow></math></span> An exact formula of the expectation <span><math><mrow><mi>E</mi><mrow><mo>[</mo><mrow><msup><mrow><mi>L</mi></mrow><mrow><mi>B</mi></mrow></msup><mrow><mo>(</mo><mi>t</mi><mo>,</mo><mi>x</mi><mo>)</mo></mrow></mrow><mo>]</mo></mrow></mrow></math></span> is given in this paper.</div></div>\",\"PeriodicalId\":36918,\"journal\":{\"name\":\"Results in Applied Mathematics\",\"volume\":\"26 \",\"pages\":\"Article 100563\"},\"PeriodicalIF\":1.4000,\"publicationDate\":\"2025-03-16\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Results in Applied Mathematics\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S2590037425000275\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"MATHEMATICS, APPLIED\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Results in Applied Mathematics","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2590037425000275","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MATHEMATICS, APPLIED","Score":null,"Total":0}
An integral representation of the local time of the Brownian motion via the Clark–Ocone formula
Let be the local time of the real-valued one-dimensional Brownian motion. In this paper, in case of a strictly increasing and bijective function, we propose some integral representations of of the form: where is a deterministic function and is a random function depending on and the cumulative distribution function of the standard normal distribution and some Brownian functionals with no Malliavin derivative. Our study is based on the case An exact formula of the expectation is given in this paper.