<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE article  PUBLIC "-//NLM//DTD Journal Publishing DTD v3.0 20080202//EN" "http://dtd.nlm.nih.gov/publishing/3.0/journalpublishing3.dtd"><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" dtd-version="3.0" xml:lang="en" article-type="research article"><front><journal-meta><journal-id journal-id-type="publisher-id">AJCM</journal-id><journal-title-group><journal-title>American Journal of Computational Mathematics</journal-title></journal-title-group><issn pub-type="epub">2161-1203</issn><publisher><publisher-name>Scientific Research Publishing</publisher-name></publisher></journal-meta><article-meta><article-id pub-id-type="doi">10.4236/ajcm.2014.41001</article-id><article-id pub-id-type="publisher-id">AJCM-42295</article-id><article-categories><subj-group subj-group-type="heading"><subject>Articles</subject></subj-group><subj-group subj-group-type="Discipline-v2"><subject>Physics&amp;Mathematics</subject></subj-group></article-categories><title-group><article-title>
 
 
  Logarithm of a Function, a Well-Posed Inverse Problem
 
</article-title></title-group><contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>ilvia</surname><given-names>Reyes Mora</given-names></name><xref ref-type="aff" rid="aff1"><sup>1</sup></xref><xref ref-type="corresp" rid="cor1"><sup>*</sup></xref></contrib><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Víctor</surname><given-names>A. Cruz Barriguete</given-names></name><xref ref-type="aff" rid="aff1"><sup>1</sup></xref></contrib><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Denisse</surname><given-names>Guzmán Aguilar</given-names></name><xref ref-type="aff" rid="aff1"><sup>1</sup></xref></contrib></contrib-group><aff id="aff1"><addr-line>Instituto de Física y Matemáticas, Universidad Tecnológica de la Mixteca, Huajuapan de León, Oax, México</addr-line></aff><author-notes><corresp id="cor1">* E-mail:<email>sreyes@mixteco.utm.mx(IRM)</email>;</corresp></author-notes><pub-date pub-type="epub"><day>22</day><month>01</month><year>2014</year></pub-date><volume>04</volume><issue>01</issue><fpage>1</fpage><lpage>5</lpage><history><date date-type="received"><day>November</day>	<month>13,</month>	<year>2013</year></date><date date-type="rev-recd"><day>December</day>	<month>13,</month>	<year>2013</year>	</date><date date-type="accepted"><day>December</day>	<month>20,</month>	<year>2013</year></date></history><permissions><copyright-statement>&#169; Copyright  2014 by authors and Scientific Research Publishing Inc. </copyright-statement><copyright-year>2014</copyright-year><license><license-p>This work is licensed under the Creative Commons Attribution International License (CC BY). http://creativecommons.org/licenses/by/4.0/</license-p></license></permissions><abstract><p>
 
 
   It poses the inverse problem that consists in finding the logarithm of a function. It shows that when the function is holomorphic in a simply connected domain , the solution at the inverse problem exists and is unique if a branch of the logarithm is fixed. In addition, it’s demonstrated that when the function is continuous in a domain , where  is Hausdorff space and connected by paths. The solution of the problem exists and is unique if a branch of the logarithm is fixed and is stable; for what in this case, the inverse problem turns out to be well-posed. 
 
</p></abstract><kwd-group><kwd>Logarithm Function; Inverse Problem; Stability</kwd></kwd-group></article-meta></front><back><ref-list><title>References</title><ref id="scirp.42295-ref1"><label>1</label><mixed-citation publication-type="other" xlink:type="simple">C. W. Groetsch, “Inverse Problems: Activities for Undergraduates,” The Mathematical Association of America, Ohio, 1999.</mixed-citation></ref><ref id="scirp.42295-ref2"><label>2</label><mixed-citation publication-type="other" xlink:type="simple">A. Browder, “Topology in the Complex Plane,” The American Mathematical Monthly, Vol. 107 No. 10, 2006, pp. 393-401.https://getinfo.de/app/Topology-in-the-Complex-Plane/id/BLSE%3ARN079983226</mixed-citation></ref><ref id="scirp.42295-ref3"><label>3</label><mixed-citation publication-type="other" xlink:type="simple">A. Hatcher, “Algebraic Topology,” Cambridge University Press, Cambridge, 2009.</mixed-citation></ref><ref id="scirp.42295-ref4"><label>4</label><mixed-citation publication-type="other" xlink:type="simple">L. V. Ahlfors, “Complex Analysis,” McGraw-Hill, New York, 1979.</mixed-citation></ref><ref id="scirp.42295-ref5"><label>5</label><mixed-citation publication-type="other" xlink:type="simple">A. Kirsch, “An Introduction to the Mathematical Theory of Inverse Problems,” 2nd Edition, Springer, Berlin, 2011.http://dx.doi.org/10.1007/978-1-4419-8474-6</mixed-citation></ref><ref id="scirp.42295-ref6"><label>6</label><mixed-citation publication-type="other" xlink:type="simple">E. Stein and R. Shakarchi, “Complex Analysis,” Princeton University Press, Princeton, 2009.</mixed-citation></ref></ref-list></back></article>