122293708
On a linearization program of non-linear field equations
Abstract The relevance of a recently developed theory of non-linear representations of Lie groups to the problem of linearization of non-linear field equations covariant under the action of a Lie group is discussed. Some basic definitions and results of this theory are then summarized. The article ends with a discussion of the physical meaning, consequences, and further possible developments of the non-linear representation theory.
122340661
Wave operators and analytic solutions for systems of non-linear Klein-Gordon equations and of non-linear Schrödinger equations
We consider, in a 1+3 space time, arbitrary (finite) systems of nonlinear Klein-Gordon equations (respectively Schrödinger equations) with an arbitrary local and analytic non-linearity in the unknown and its first and second order space-time (respectively first order space) derivatives, having no constant or linear terms. No restriction is given on the frequency sign of the initial data. In the case of non-linear Klein-Gordon equations all masses are supposed to be different from zero.We prove, for such systems, that the wave operator (fromt=∞ tot=0) exists on a domain of small entire test functions of exponential type and that the analytic Cauchy problem, in ℝ+×ℝ3, has a unique solution for each initial condition (att=0) being in the image of the wave operator. The decay properties of such solutions are discussed in detail.
122026820
Field Theory on Curved Space Time and the TCP Theorem
A generalization is given to the Wightman axioms of field theory which permits to treat gravitational field as a Wightman field. This generalization permits to deduce TCP theorem for the gravitational field. The note ends with some critical remarks concerning the physical interpretation of the TCP theorem.
119567009
Yang-Mills equations are formally linearizable
It is proved, in the framework of a recent theory of non-linear group representations elaborated by the authors, that the non-linear Yang-Mills equations are formally linearizable: there exists a formal non-linear operator which intertwins the non-linear Yang-Mills equations with their free (linear) part.
120008134
A wave operator for a non-linear Klein-Gordon equation
We prove the existence of a set of initial data to which correspond solutions of the nonlinear Klein-Gordon equation with a polynomial nonlinear term, which converge asymptotically, when t→+∞, to solutions of the linear Klein-Gordon equation.
119881917
Linearization of relativistic nonlinear wave equations
Some linearization theorems for relativistic nonlinear wave equations are formulated and proved. Examples are discussed and the physical meaning of such a linearization is sketched. Finally, some remarks concerning gauge theories are presented.
15382595
Hamiltonian thermodynamics of a Lovelock black hole
We consider the Hamiltonian dynamics and thermodynamics of spherically symmetric spacetimes within a one-parameter family of five-dimensional Lovelock theories. We adopt boundary conditions that make every classical solution part of a black hole exterior, with the spacelike hypersurfaces extending from the horizon bifurcation three-sphere to a timelike boundary with fixed intrinsic metric. The constraints are simplified by a Kuchar ˇ-type canonical transformation, and the theory is reduced to its true dynamical degrees of freedom. After quantization, the trace of the analytically continued Lorentzian time evolution operator is interpreted as the partition function of a thermodynamical canonical ensemble. Whenever the partition function is dominated by a Euclidean black hole solution, the entropy is given by the Lovelock analogue of the Bekenstein-Hawking entropy; in particular, in the low temperature limit the system exhibits a dominant classical solution that has no counterpart in Einstein’s theory. The asymptotically flat space limit of the partition function does not exist. The results indicate qualitative robustness of the thermodynamics of five-dimensional Einstein theory upon the addition of a nontrivial Lovelock term. @S0556-2821~97!03806-X#
10977212
Exotic gauge theories from tensor calculus
We construct non-standard interactions between exterior form gauge fields by gauging a particular global symmetry of the Einstein-Maxwell action for such fields. Furthermore, we discuss generalizations of such interactions by adding couplings to gravitational Chern-Simons forms and to fields arising through dimensional reduction. The construction uses an appropriate tensor calculus.
192916821
The NEXT experiment for neutrinoless double beta decay searches
The goal of the NEXT experiment is the observation of the neutrinoless double beta decay in 136Xe using a gaseous xenon TPC with electroluminescent amplification and specialized photodetector arrays for calorimetry and tracking. After a prototyping period (2009-2014) where the technique was demonstrated, the Collaboration has completed the construction and started the operation of its first phase (NEXT-White or NEW) in the Laboratorio Subterraneo de Canfranc, in the Spanish Pyrenees, with the objectives of measuring in-situ the NEXT background model and the two-neutrino mode of the double beta decay under a radiopure regime. After running NEW, the Collaboration will operate a bigger detector, NEXT-100, which will look for the neutrinoless decay mode.
123342407
General relativity in a (2+1)-dimensional space-time: An electrically charged solution
AbstractWe have found a static electrically charged solution to the Einstein-Maxwell equations in a (2+1)-dimensional space-time. Studies of general relativity in lower dimensional space-times provide many new insights and a simplified arena for doing quantum mechanics. In (2+1)-dimensional space-time, solutions to the vacuum field equations are locally flat (point masses are conical sigularities), but when electromagnetic fields are presentTab≠O and the solutions are curved. For a static chargeQ we find
$$\mathop E\limits^ \to = Q\hat r/r$$
 andds2= −(kQ2/2π)In(rc/r)dt2 + (2π/kQ2[ln(rc/r)]−1dr2 +r2dφ2 whererc is a constant. There is a horizon atr =rc like the inner horizon of the Reisner-Nordström solution. We have produced a Kruskal extension of this metric which shows two static regions (I and III) withr rc. A spacelike slice across regions I and III shows a football-shaped universe with chargeQ at one end and −Q at the other. Slices in the dynamical regions (II and IV) show a cylindrical universe that is expanding in region II and contracting in region IV. Electromagnetic solutions to the Einstein-Maxwell field equations in lower dimensional space-times can be used to provide new insights into Kaluza-Klein theories. In terms of the Kaluza-Klein theory, for example, electromagnetic radiation in a (2+1)-dimensional space-time is really gravitational radiation in the associated (3+1)-dimensional Kaluza-Klein space-time. According to Kaluza Klein theory the absence of gravitational radiation in (2+1)-dimensional space-time implies (correctly) the absence of electromagnetic radiation in (1+1)-dimensional space-time.
117296504
WORLD VOLUME REALIZATION OF AUTOMORPHISMS
The relation among spacetime supersymmetry algebras and the world volume approach to string theory is reviewed. The realization of some of the automorphism transformations of these superalgebras on the world volume theory is discussed. We distinguish among linear realizations and non-local ones. The consistency of the latter with duality in M/string theory is checked.