Mark Trodden
Encyclopedia
Mark Trodden is a theoretical cosmologist and particle physicist. He is the Fay R. and Eugene L. Langberg Professor of Physics and Co-Director of the Center for Particle Cosmology at the University of Pennsylvania
.
and obtained his Ph.D. degree in 1995. He worked as a Research Associate for two years at MIT and two years at Case Western Reserve University
after getting his Ph.D. From 2000 to 2009, Trodden was a faculty member at Syracuse University
, holding the Alumni Professorship from 2005 to 2009.
, General Relativity
, and Superstring Theories
. Trodden, with Sean Carroll
, introduced a new class of topological defect
s in ordinary field theories. Trodden's work in theoretical studies and understanding of the early universe
has been widely cited and relied upon by the scientific community.
Specifically, Trodden's research focuses on configurations consisting of topological solitons which end on others of equal or higher dimension. In such models, the higher dimensional defect provides Dirichlet boundary conditions for the lower dimensional one.
Trodden, with his co-workers Anne-Christine Davis and Steven Davis, has also investigated the particle physics
and cosmological properties of topological defects in supersymmetic
theories. Their first study, dealing with abelian theories
demonstrated that all spontaneously broken abelian supersymmetric theories admit cosmic string solutions which are superconducting due to fermion
zero modes. Further, by using supersymmetry transformations, they showed how to calculate the supercurrents in terms of the background string fields
. They also managed to extended these results to non-abelian theories
and investigated the effects of soft supersymmetry breaking.
Trodden describes himself as a "particle cosmologist."
University of Pennsylvania
The University of Pennsylvania is a private, Ivy League university located in Philadelphia, Pennsylvania, United States. Penn is the fourth-oldest institution of higher education in the United States,Penn is the fourth-oldest using the founding dates claimed by each institution...
.
Education and career
Trodden received both his Bachelor (mathematics) degree and a Certificate of Advanced Study in Mathematics (Part III) from Cambridge University. He subsequently spent a year doing research and supervising undergraduates at Cambridge University. In 1992, Trodden moved to the USA to enter the Ph.D. program at Brown UniversityBrown University
Brown University is a private, Ivy League university located in Providence, Rhode Island, United States. Founded in 1764 prior to American independence from the British Empire as the College in the English Colony of Rhode Island and Providence Plantations early in the reign of King George III ,...
and obtained his Ph.D. degree in 1995. He worked as a Research Associate for two years at MIT and two years at Case Western Reserve University
Case Western Reserve University
Case Western Reserve University is a private research university located in Cleveland, Ohio, USA...
after getting his Ph.D. From 2000 to 2009, Trodden was a faculty member at Syracuse University
Syracuse University
Syracuse University is a private research university located in Syracuse, New York, United States. Its roots can be traced back to Genesee Wesleyan Seminary, founded by the Methodist Episcopal Church in 1832, which also later founded Genesee College...
, holding the Alumni Professorship from 2005 to 2009.
Research
Mark Trodden's main research areas are the cosmological implications of Quantum Field TheoriesQuantum field theory
Quantum field theory provides a theoretical framework for constructing quantum mechanical models of systems classically parametrized by an infinite number of dynamical degrees of freedom, that is, fields and many-body systems. It is the natural and quantitative language of particle physics and...
, General Relativity
General relativity
General relativity or the general theory of relativity is the geometric theory of gravitation published by Albert Einstein in 1916. It is the current description of gravitation in modern physics...
, and Superstring Theories
Superstring theory
Superstring theory is an attempt to explain all of the particles and fundamental forces of nature in one theory by modelling them as vibrations of tiny supersymmetric strings...
. Trodden, with Sean Carroll
Sean M. Carroll
Sean Michael Carroll is a senior research associate in the Department of Physics at the California Institute of Technology. He is a theoretical cosmologist specializing in dark energy and general relativity...
, introduced a new class of topological defect
Topological defect
In mathematics and physics, a topological soliton or a topological defect is a solution of a system of partial differential equations or of a quantum field theory homotopically distinct from the vacuum solution; it can be proven to exist because the boundary conditions entail the existence of...
s in ordinary field theories. Trodden's work in theoretical studies and understanding of the early universe
Universe
The Universe is commonly defined as the totality of everything that exists, including all matter and energy, the planets, stars, galaxies, and the contents of intergalactic space. Definitions and usage vary and similar terms include the cosmos, the world and nature...
has been widely cited and relied upon by the scientific community.
Specifically, Trodden's research focuses on configurations consisting of topological solitons which end on others of equal or higher dimension. In such models, the higher dimensional defect provides Dirichlet boundary conditions for the lower dimensional one.
Trodden, with his co-workers Anne-Christine Davis and Steven Davis, has also investigated the particle physics
Particle physics
Particle physics is a branch of physics that studies the existence and interactions of particles that are the constituents of what is usually referred to as matter or radiation. In current understanding, particles are excitations of quantum fields and interact following their dynamics...
and cosmological properties of topological defects in supersymmetic
Supersymmetry
In particle physics, supersymmetry is a symmetry that relates elementary particles of one spin to other particles that differ by half a unit of spin and are known as superpartners...
theories. Their first study, dealing with abelian theories
Abelian category
In mathematics, an abelian category is a category in which morphisms and objects can be added and in which kernels and cokernels exist and have desirable properties. The motivating prototype example of an abelian category is the category of abelian groups, Ab. The theory originated in a tentative...
demonstrated that all spontaneously broken abelian supersymmetric theories admit cosmic string solutions which are superconducting due to fermion
Fermion
In particle physics, a fermion is any particle which obeys the Fermi–Dirac statistics . Fermions contrast with bosons which obey Bose–Einstein statistics....
zero modes. Further, by using supersymmetry transformations, they showed how to calculate the supercurrents in terms of the background string fields
String field theory
String field theory is a formalism in string theory in which the dynamics of relativistic strings is reformulated in the language of quantum field theory...
. They also managed to extended these results to non-abelian theories
Non-abelian class field theory
In mathematics, non-abelian class field theory is a catchphrase, meaning the extension of the results of class field theory, the relatively complete and classical set of results on abelian extensions of any number field K, to the general Galois extension L/K...
and investigated the effects of soft supersymmetry breaking.
Trodden describes himself as a "particle cosmologist."
Academic papers
- Mark Trodden, et al., Is Cosmic Speed-Up Due to New Gravitational Physics?, Physical ReviewPhysical ReviewPhysical Review is an American scientific journal founded in 1893 by Edward Nichols. It publishes original research and scientific and literature reviews on all aspects of physics. It is published by the American Physical Society. The journal is in its third series, and is split in several...
, 2004. - Mark Trodden, et al., Can the dark energy equation-of-state parameter w be less than -1?, Physical ReviewPhysical ReviewPhysical Review is an American scientific journal founded in 1893 by Edward Nichols. It publishes original research and scientific and literature reviews on all aspects of physics. It is published by the American Physical Society. The journal is in its third series, and is split in several...
, 2003. - Mark Trodden, et al., The State of the Dark Energy Equation of State, Physical ReviewPhysical ReviewPhysical Review is an American scientific journal founded in 1893 by Edward Nichols. It publishes original research and scientific and literature reviews on all aspects of physics. It is published by the American Physical Society. The journal is in its third series, and is split in several...
, 2003.
External links
- Mark Trodden's personal website
- Mark Trodden's papers in SPIRES database
- Videos (with mp3s available) of discussions on physics/cosmology with Trodden on Bloggingheads.tvBloggingheads.tvBloggingheads.tv is a political, world events, philosophy, and science video blog discussion site in which the participants take part in an active back and forth conversation via webcam which is then broadcast online to viewers...