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Geometrical resolution of spacetime singularities

Frederik De Roo UGent (2010)
abstract
General relativity predicts the existence of gravitational singularities at the classical level: our universe started with the big bang, and massive stars can collapse into black holes. A theory that describes quantum gravitational effects should elucidate our understanding of these singularities. The existence of these singularities also raises the question whether propagation of quantum fields through a singularity is possible (and how it should be formulated). String theory can already deal with some timelike singularities but not yet with spacelike singularities like the big bang. Near singularities, strings often interact strongly. A formulation of string theory that allows to take strong interactions between strings into account is given by matrix theory. Matrix theory models that describe singularities often have a dual translation in terms of a quantum field theory that is defined on a singular background spacetime. In this dissertation we investigate these issues. We use a geometric regularization prescription to define the evolution of a free scalar field and of a free string through a singularity in an unambiguous manner. Remarkably, this geometric regularization seems to reveal there is a certain feature of discreteness related to the evolution across the singularity. We also consider an important class of time-dependent backgrounds that can be investigated in string theory. This class is called gravitational plane waves. These plane waves can be used to investigate the strong curvature effects related to a singularity. Our study shows that it is necessary to take into account that the strings can interact strongly near the singularity. In order to obtain a better understanding of matrix theory on a plane wave background we investigate solutions that describes D-branes in plane wave backgrounds. D-branes are objects that appear in string theory besides strings, and that are important for the formulation of matrix theory.
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author
promoter
Ben Craps and Greet Maenhout
organization
alternative title
Geometrische resolutie van ruimte-tijd-singulariteiten
year
type
dissertation
publication status
published
subject
pages
XX, 270 pages
publisher
Vrije Universiteit Brussel. Faculty of Science and Bio-engineering Sciences ; Ghent University. Faculty of Engineering
place of publication
Brussels ; Ghent, Belgium
defense location
Gent : Faculteit Ingenieurswetenschappen (Jozef Plateauzaal)
defense date
2010-07-01 15:30
ISBN
9789085783664
language
English
UGent publication?
yes
classification
D1
additional info
PhD Dissertation of a Joint PhD between Free University of Brussels (Department of Physics) and Ghent University (Department of Electrical energy, systems and automation). The PhD advisor at VUB is Prof. Ben Craps, and the PhD advisor at UGent is prof ir Greet Maenhout.
copyright statement
I have retained and own the full copyright for this publication
id
1029255
handle
http://hdl.handle.net/1854/LU-1029255
date created
2010-08-27 08:37:23
date last changed
2017-01-16 10:37:56
@phdthesis{1029255,
  abstract     = {General relativity predicts the existence of gravitational singularities at the classical level: our universe started with the big bang, and massive stars can collapse into black holes. A theory that describes quantum gravitational effects should elucidate our understanding of these singularities. The existence of these singularities also raises the question whether propagation of quantum fields through a singularity is possible (and how it should be formulated). String theory can already deal with some timelike singularities but not yet with spacelike singularities like the big bang. Near singularities, strings often interact strongly. A formulation of string theory that allows to take strong interactions between strings into account is given by matrix theory. Matrix theory models that describe singularities often have a dual translation in terms of a quantum field theory that is defined on a singular background spacetime.
In this dissertation we investigate these issues. We use a geometric regularization prescription to define the evolution of a free scalar field and of a free string through a singularity in an unambiguous manner. Remarkably, this geometric regularization seems to reveal there is a certain feature of discreteness related to the evolution across the singularity. We also consider an important class of time-dependent backgrounds that can be investigated in string theory. This class is called gravitational plane waves. These plane waves can be used to investigate the strong curvature effects related to a singularity. Our study shows that it is necessary to take into account that the strings can interact strongly near the singularity. In order to obtain a better understanding of matrix theory on a plane wave background we investigate solutions that describes D-branes in plane wave backgrounds. D-branes are objects that appear in string theory besides strings, and that are important for the formulation of matrix theory.},
  author       = {De Roo, Frederik},
  isbn         = {9789085783664},
  language     = {eng},
  pages        = {XX, 270},
  publisher    = {Vrije Universiteit Brussel. Faculty of Science and Bio-engineering Sciences ; Ghent University. Faculty of Engineering},
  school       = {Ghent University},
  title        = {Geometrical resolution of spacetime singularities},
  year         = {2010},
}

Chicago
De Roo, Frederik. 2010. “Geometrical Resolution of Spacetime Singularities”. Brussels ; Ghent, Belgium: Vrije Universiteit Brussel. Faculty of Science and Bio-engineering Sciences ; Ghent University. Faculty of Engineering.
APA
De Roo, F. (2010). Geometrical resolution of spacetime singularities. Vrije Universiteit Brussel. Faculty of Science and Bio-engineering Sciences ; Ghent University. Faculty of Engineering, Brussels ; Ghent, Belgium.
Vancouver
1.
De Roo F. Geometrical resolution of spacetime singularities. [Brussels ; Ghent, Belgium]: Vrije Universiteit Brussel. Faculty of Science and Bio-engineering Sciences ; Ghent University. Faculty of Engineering; 2010.
MLA
De Roo, Frederik. “Geometrical Resolution of Spacetime Singularities.” 2010 : n. pag. Print.