{"id":343,"date":"2026-05-06T14:23:54","date_gmt":"2026-05-06T17:23:54","guid":{"rendered":"https:\/\/www.ccen.ufpb.br\/ppgf\/?p=343"},"modified":"2026-05-06T14:23:54","modified_gmt":"2026-05-06T17:23:54","slug":"coloquio-platypus-stars-vacuum-stars-as-an-alternative-to-gravastars-gonzalo-j-olmo","status":"publish","type":"post","link":"https:\/\/www.ccen.ufpb.br\/ppgf\/ciclo-de-coloquios\/coloquio-platypus-stars-vacuum-stars-as-an-alternative-to-gravastars-gonzalo-j-olmo\/","title":{"rendered":"Col\u00f3quio: Platypus Stars: Vacuum Stars as an Alternative to Gravastars (Gonzalo J. Olmo)"},"content":{"rendered":"<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"243\" height=\"384\" src=\"https:\/\/www.ccen.ufpb.br\/ppgf\/wp-content\/uploads\/sites\/115\/sites\/445\/2026\/05\/foto-coloq-6.png\" alt=\"\" class=\"wp-image-344\" srcset=\"https:\/\/www.ccen.ufpb.br\/ppgf\/wp-content\/uploads\/sites\/115\/sites\/445\/2026\/05\/foto-coloq-6.png 243w, https:\/\/www.ccen.ufpb.br\/ppgf\/wp-content\/uploads\/sites\/115\/sites\/445\/2026\/05\/foto-coloq-6-190x300.png 190w\" sizes=\"auto, (max-width: 243px) 100vw, 243px\" \/><\/figure>\n<\/div>\n\n\n<p class=\"wp-block-paragraph\">Ciclo de Col\u00f3quios 2026.1<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Col\u00f3quio #06<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u201cPlatypus Stars: Vacuum Stars as an Alternative to Gravastars\u201d<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Prof. Dr.&nbsp;Gonzalo J. Olmo<br>Department of Theoretical Physics &amp; IFIC, University of Valencia \u2013 CSIC<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Sexta-feira, 08 de maio de 2026, \u00e0s 14h, na&nbsp;sala 201 do Departamento de F\u00edsica\/CCEN.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">RESUMO: Gravastars are often presented as horizonless alternatives to black holes, supported by the energy and pressure associated with a cosmological constant. In this talk, I will show that, if vacuum energy is treated as truly empty space (rather than as a cosmological constant), it is possible to construct a new type of stellar object based on this premise within General Relativity, using the Tolman\u2013Oppenheimer\u2013Volkoff (TOV) equations. I will describe the structural properties of these objects, discuss aspects of the matching conditions involved, and analyze their compactness as well as the behavior of null geodesics in these geometries.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Ciclo de Col\u00f3quios 2026.1 Col\u00f3quio #06 \u201cPlatypus Stars: Vacuum Stars as an Alternative to Gravastars\u201d [&hellip;]<\/p>\n","protected":false},"author":522,"featured_media":231,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[],"class_list":["post-343","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-ciclo-de-coloquios"],"_links":{"self":[{"href":"https:\/\/www.ccen.ufpb.br\/ppgf\/wp-json\/wp\/v2\/posts\/343","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.ccen.ufpb.br\/ppgf\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.ccen.ufpb.br\/ppgf\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.ccen.ufpb.br\/ppgf\/wp-json\/wp\/v2\/users\/522"}],"replies":[{"embeddable":true,"href":"https:\/\/www.ccen.ufpb.br\/ppgf\/wp-json\/wp\/v2\/comments?post=343"}],"version-history":[{"count":1,"href":"https:\/\/www.ccen.ufpb.br\/ppgf\/wp-json\/wp\/v2\/posts\/343\/revisions"}],"predecessor-version":[{"id":345,"href":"https:\/\/www.ccen.ufpb.br\/ppgf\/wp-json\/wp\/v2\/posts\/343\/revisions\/345"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.ccen.ufpb.br\/ppgf\/wp-json\/wp\/v2\/media\/231"}],"wp:attachment":[{"href":"https:\/\/www.ccen.ufpb.br\/ppgf\/wp-json\/wp\/v2\/media?parent=343"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ccen.ufpb.br\/ppgf\/wp-json\/wp\/v2\/categories?post=343"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ccen.ufpb.br\/ppgf\/wp-json\/wp\/v2\/tags?post=343"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}