https://wiki.nivel-teorico.com/index.php?action=history&feed=atom&title=Geometria_qu%C3%A2ntica 2026-09-08T01:39:01Z Histórico de edições para esta página nesta wiki MediaWiki 1.40.1 https://wiki.nivel-teorico.com/index.php?title=Geometria_qu%C3%A2ntica&diff=6127&oldid=prev 2013-05-03T11:41:40Z

<p>uma edição</p> <p><b>Página nova</b></p><div>Em [[física teórica]], &#039;&#039;&#039;geometria quântica&#039;&#039;&#039; é o conjunto de novos conceitos matemáticos generalizando os conceitos de [[geometria]] cujo entendimento é necessário para descrever os fenômenos físicos em distâncias de escala extremamente pequena (comparáveis ao [[comprimento de Planck]]). Nestas distâncias, a [[mecânica quântica]] tem profundo efeito sobre a física.<br /> <br /> &lt;!-- <br /> <br /> Each theory of [[quantum gravity]] uses the term &#039;&#039;quantum geometry&#039;&#039; in a slightly different fashion. [[String theory]], a leading candidate for a quantum theory of gravity, uses the term quantum geometry to describe exotic phenomena such as [[T-duality]] and other geometric dualities, [[mirror symmetry]], [[topology]]-changing transitions, minimal possible distance scale, and other effects that challenge our usual geometrical intuition. More technically, quantum geometry refers to the shape of the spacetime manifold as seen by [[D-branes]] which includes the quantum corrections to the [[metric tensor]], such as the worldsheet [[instanton]]s. For example, the quantum volume of a cycle is computed from the mass of a [[brane]] wrapped on this cycle.<br /> <br /> In an alternative approach to quantum gravity called [[loop quantum gravity]] (LQG), the phrase &#039;&#039;&#039;&#039;&#039;quantum geometry &#039;&#039;&#039;&#039;&#039; usually refers to the [[Scientific formalism|formalism]] within LQG where the observables that capture the information about the geometry are now well defined operators on a [[Hilbert space]]. In particular, certain physical [[observable]]s, such as the area, have a [[discrete spectrum]]. It has also been shown that the loop quantum geometry is [[non-commutative geometry|non-commutative]].<br /> <br /> It is possible (but considered unlikely) that this strictly quantized understanding of geometry will be consistent with the quantum picture of geometry arising from string theory.<br /> <br /> Another approach, which tries to reconstruct the geometry of space-time from &quot;first principles&quot; is [[Discrete Lorentzian quantum gravity]].<br /> <br /> --&gt;<br /> <br /> == Ver também ==<br /> <br /> * [[Geometria não comutativa]]<br /> * [[Gravidade quântica em loop]]<br /> <br /> == Ligações externas ==<br /> * [http://cgpg.gravity.psu.edu/people/Ashtekar/articles/spaceandtime.pdf Space and Time: From Antiquity to Einstein and Beyond] {{en}}<br /> * [http://cgpg.gravity.psu.edu/people/Ashtekar/articles/qgfinal.pdf Quantum Geometry and its Applications] {{en}}<br /> <br /> {{esboço-física}}<br /> <br /> [[Categoria:Mecânica quântica]]<br /> [[Categoria:Física teórica]]<br /> [[Categoria:Gravidade quântica]]</div>

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