Ergopodručja

master's thesis

• Title (english): Ergoregions
• Author: Ana Bokulić
• Mentor: Ivica Smolić (mentor)
• Committee member: Ivica Smolić (predsjednik povjerenstva)
• Committee member: Maro Cvitan (član povjerenstva)
• Committee member: Matko Milin (član povjerenstva)
• Committee member: Davor Horvatić (član povjerenstva)
• Committee member: Mihael Makek (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Physics); Zagreb
• Defense date and country: 2019-08-27, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Physics

Abstract

Lense-Thirringova precesija općerelativistički je efekt koji nastaje kao posljedica ”povlačenja” prostorvremena oko rotirajućeg tijela. Efekt se opaža i u blizini Zemlje, gdje je eksperimentalno provjeren sondom Gravity Probe B. Ekstremni oblik Lense- Thirringove precesije javlja se u ergopodručjima, dijelovima prostorvremena unutar kojih su svi fizikalni promatrači prisiljeni rotirati zajedno s objektom koji ju uzrokuje. Zbog svojih svojstava, ergopodručja omogućuju ekstrakciju rotacijske energije objekta mehanizmima kao što je Penroseov proces. U ovom je radu opisana geometrija ergopodručja koja se pojavljuju u rješenjima Einsteinove jednadžbe, s posebnim naglaskom na klasu slabo omedenih ergopodručja. Uz to, analizirane su efikasnosti Penroseovog procesa i njegovih inačica u različitim vrstama prostorvremena.

Abstract (english)

Lense-Thirring precession is an effect predicted by general relativity which arises due to the dragging of spacetime near rotating body. This effect can be observed in the vicinity of Earth, where it was experimentally confirmed using the Gravity Probe B satellite. Extreme version of Lense-Thirring precession can be found inside ergoregions, parts of spacetime in which all physical observers must corotate with the object causing the aforementioned effect. Because of its properties, it is possible to extract rotational energy from ergoregions via physical mechanisms such as Penrose process. In this work we will describe the geometry of the ergoregions that appear in the solutions of Einstein’s equation, with special emphasis on a subclass of ergoregions called weakly bounded. Additionally, we analyse the efficiency of Penrose process and its variants in different types of spacetimes.

• Keywords: crne rupe; Kerrovo prostorvrijeme; rotirajuće crvotočine; Lense- Thirringova precesija; Penroseov proces
• Keywords (english): black holes; Kerr spacetime; rotating wormholes; Lense-Thirring precession; Penrose process
• Language: croatian
• URN:NBN: urn:nbn:hr:217:508276
• Study programme: Title: Physics; specializations in: Research; Course: Research; Study programme type: university; Study level: integrated undergraduate and graduate; Academic / professional title: magistar/magistra fizike (magistar/magistra fizike)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2020-01-07 10:03:20