Matej Pavsic Home Page

         Matej Pavsic

         The Landscape of Theoretical Physics: A Global View;
         From Point Particles to the Brane World and Beyond, in Search of a Unifying Principle
         (Kluwer Academic Publisher, 2001)

         My comments on the book

   This is a book for anybody who would like to learn something about special and general relativity beyond the usual textbooks, about quantum field theory, the elegant Fock-Schwinger-Stueckelberg proper time formalism, the elegant description of geometry by means of Clifford algebra, about the fascinating possibilities the latter algebra offers in reformulating the existing physical theories and quantizing them in a natural and obvious way. The theory of branes and the idea of how a 3-brane might represent our world is discussed in detail. Much attention is paid to the elegant geometric theory of branes which employs the infinite dimensional space of functions describing branes. Clifford algebra is generalized to the infinite dimensional spaces.

In short, this is a book for anybody who would like to explore how the ``theory of everything'' might possibly be formulated. The theory that would describe all the known phenomena, could not be formulated without taking into account all the theoretical tools which are available. Foundations of those tools and their functional interrelations are described in the book.

In 70's I was amongst those rare researchers who were studying higher dimensional, Kaluza-Klein, theories. Moreover, I was taking the extra dimensions seriously, basically on the same footing as the more familiar four dimensions, and did not try to impose certain constraints into the action in order to assure the isometry along the extra dimensions, as was the common practice at that time. As a starting point I considered just the Einstein-Hilbert action plus ``matter'' in higher dimensional spacetime. In 80's I was one of the very few who were taking seriously the idea that our 4-dimensional spacetime is a brane embedded in a higher dimensional space, and obeys the dynamics which is a straightforward extension of the point particle dynamics. The path of the brane (3-brane) representing our world is a minimal 4-surface in the embedding space. Nowadays I am still one of those not so many physicists who are seriously considering the idea that quantum mechanics cannot be fully understood without admitting that a wave function is relative to an observer. But there are hints of such an idea in the works of a number of more or less known physicists. The book touches such fascinating topics in the last part entitled ``Beyond the Horizon''. Not only the physicists, but also others who are interested in the foundations of quantum mechanics and the role of the observer are likely to profit from the book. Its main underlying message is that there is no ``unified theory'' (whatever it means) without the unification of diverse branches of theoretical physics, the corresponding mathematical techniques and the underlying concepts. The book provides a global view of all that.

This book could also be used as a textbook of a specially designed postgraduate course aiming at giving a synthetic view of fundamental theoretical physics. In the approaches adopted so far too much specialized treatment of topics has been at the expense of seeing the whole picture. The result is not so good as it could be: after so many decades of research we are still searching for a quantum theory of gravity and other interactions. The book provides the ingredients which all will have very likely to be used in order to build the ``final theory''. No final theory is proposed in the book, but several hints are expounded.

Matej Pavsic

Full text of the book available now Pdf Ps ArXiv gr-qc/0610061
(with kind permission of Springer)