Traversable Wormholes and the Simpson-Visser Model

Δορλής, Παναγιώτης; Dorlis, Panagiotis

dc.contributor.author	Δορλής, Παναγιώτης	el
dc.contributor.author	Dorlis, Panagiotis	en
dc.date.accessioned	2022-02-09T12:22:37Z
dc.date.available	2022-02-09T12:22:37Z
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/54615
dc.identifier.uri	http://dx.doi.org/10.26240/heal.ntua.22313
dc.rights	Default License
dc.subject	Σκουληκότρυπες	el
dc.subject	Γενική Θεωρία της Σχετικότητας	el
dc.subject	Wormholes	en
dc.subject	Traversable	en
dc.title	Traversable Wormholes and the Simpson-Visser Model	en
dc.contributor.department	Εθνικό Μετσόβιο Πολυτεχνείο--Μεταπτυχιακή Εργασία. Διεπιστημονικό-Διατμηματικό Πρόγραμμα Μεταπτυχιακών Σπουδών (Δ.Π.Μ.Σ.) “Φυσική και Τεχνολογικές Εφαρμογές”	el
heal.type	masterThesis
heal.classification	Φυσική	el
heal.language	en
heal.access	free
heal.recordProvider	ntua	el
heal.publicationDate	2021-06-24
heal.abstract	The goal of this thesis is to extend the Simpson-Visser technique for regularising the Schwarzschild metric by the introduction of a cosmological constant and charge. Before that, this thesis starts with an introduction that clarifies that the Schwarzschild black hole, even if it possesses a wormhole-like geometry, is not a traversable wormhole; something that is forbidden by the principle of General Relativity. After that, we pose the basic criteria for a metric to describe a traversable wormhole in principle. This is a review for traversable wormholes in the sense of Morris and Thorne, in which the Bronnikov formalism is enforced. Wormholes are characterized as static and spherical symmetric spacetimes without centre and horizons; that is, a geometry possessing a minimum coordinate sphere radius different than zero, which is the definition of the throat of the wormhole and no null Killing horizons, which is the definition of a horizon in this class of spacetimes. In order to succeed that, a NEC violating Energy-Momentum tensor is unavoidable, so "exotic matter" is appropriate for the structure of the throat. After, recovering the original Morris and Thorne formalism and present the simplest example of a wormhole, we extract the Penrose diagram of such a spacetime in order to illustrate its causal structure. A causal structure which is like that of Minkowski, but with a different interpretation. What we are going to see in chapter 3 is the technique of Simpson and Visser in order to regularize the Schwarzschild metric by the introduction of some parameter η. Specifically, on the values of this parameter depends the kind of the geometry that the metric describes, starting from the original Schwarzschild black hole to a traversable wormhole. For the wormhole, it turns out that this parameter corresponds to the throat radius. The intermediate "states" are those of a regular black hole and a one-way traversable wormhole. We present this technique in its general state, which allows us to extend the technique of Simpson and Visser to more spacetimes rather than the Schwarzschild one. Namely, we extend this procedure by introducing a cosmological constant and charge (Reissner–Nordström). In chapter 4, we present an observational distinction between the initial black hole and the corresponding wormhole. With the circular orbits being our tool, we see that as we grow the parameter η , the ISCO and the photon sphere become smaller and smaller until their final disappearance. In the final chapter, some comments for future work on this spacetimes are presented.	en
heal.advisorName	Παπαντωνόπουλος, Ελευθέριος	el
heal.committeeMemberName	Παπαντωνόπουλος, Λευτέρης	el
heal.committeeMemberName	Σαρηδάκης, Μανόλης	el
heal.committeeMemberName	Κουτσούμπας, Γιώργος	el
heal.academicPublisher	Εθνικό Μετσόβιο Πολυτεχνείο. Σχολή Εφαρμοσμένων Μαθηματικών και Φυσικών Επιστημών	el
heal.academicPublisherID	ntua
heal.numberOfPages	80 σ.	el
heal.fullTextAvailability	false