118605658
Geometric Representation of Interacting Non-Relativistic Open Strings using Extended Objects
Non-relativistic charged open strings coupled with Abelian gauge fields are quantized in a geometric representation that generalizes the Loop Representation. The model consists of open-strings interacting through a Kalb-Ramond field in four dimensions. The geometric representation proposed uses lines and surfaces that can be interpreted as an extension of the picture of Faraday's lines of classical electromagnetism. This representation results to be consistent, provided the coupling constant (the "charge" of the string) is quantized. The Schr\"odinger equation in this representation is also presented.
126306149
QUANTUM ABELIAN SURFACES
16377160
Topological sectors and gauge invariance in massive vector-tensor theories in D≥4
Abstract A family of locally equivalent models is considered. They can be taken as a generalization to d + 1 dimensions of the Topological Massive and “Self-dual” models in 2+1 dimensions. The corresponding 3+1 models are analized in detail. It is shown that one model can be seen as a gauge fixed version of the other, and their space of classical solutions differs in a topological sector represented by the classical solutions of pure BF model. The topological sector can be gauged out on cohomologically trivial base manifolds but on general settings it may be responsible of the difference in the long distance behaviour of the models. The presence of this topological sector appears explicitly in the partition function of the theories. The generalization of this models to higher dimensions is shown to be straightfoward.
119183090
SELF-DUAL FORMULATIONS OF d = 3 GRAVITY THEORIES IN THE PATH-INTEGRAL FRAMEWORK
We study the connection, at the quantum level, between (d = 2+1)-dimensional self-dual models with actions of growing (from first to fourth) order, governing the dynamics of helicity ±2 massive excitations. We obtain identities between generating functionals of the different models using the path-integral framework, this allowing us to establish dual maps among relevant vacuum expectation values. We check consistency of these vacuum expectation values with the gauge invariance gained in each mapping.
53942626
Interacting particles and strings in path and surface representations
Nonrelativistic charged particles and strings coupled with Abelian gauge fields are quantized in a geometric representation that generalizes the loop representation. We consider three models: the string in self-interaction through a Kalb-Ramond field in four dimensions, the topological interaction of two particles due to a BF term in $2+1$ dimensions, and the string-particle interaction mediated by a BF term in $3+1$ dimensions. In the first case one finds that a consistent ``surface representation'' can be built provided that the coupling constant is quantized. The geometrical setting that arises corresponds to a generalized picture of the lines of Faraday: quantum states are labeled by the shape of the string, from which emanate ``Faraday's surfaces.'' In the other models, the topological interaction can also be described by geometrical means. It is shown that the open-path (or open-surface) dependence carried by the wave functional in these models can be eliminated through a unitary transformation, except by the remaining dependence on the boundary of the path (or surface). This feature is closely related to the presence of anomalous statistics in the $2+1$ model, and to a generalized ``anyonic behavior'' of the string in the other case.
118459607
Quantization of Interacting Non-Relativistic Open Strings using Extended Objects
Non-relativistic charged open strings coupled with Abelian gauge fields are quantized in a geometric representation that generalizes the Loop Representation. The model comprises open-strings interacting through a Kalb-Ramond field in four dimensions. It is shown that a consistent geometric-representation can be built using a scheme of ``surfaces and lines of Faraday'', provided that the coupling constant (the ``charge'' of the string) is quantized.
119184475
Effects of heavy bosonic excitations on QED vacuum
We discuss the contribution of axion-like excitations (ALE) to the vacuum birefringence in the limit mA ≳ ω, where mA is the mass of the excitation and ω the energy of test photons interacting with an external (intense) magnetic field. The relevance of this term with respect to the QED contribution depends on the ratio gA/mA and, from present bounds on the mass and the coupling constant gA, we find that in the present low energy regime, it ranges from 10-14 to 102 suggesting an interesting alternative to explore.
118864167
Cosmic Neutrino Background as a Ferromagnet
Abstract If cosmic background neutrinos interact very weakly with each other, through spin–spin interactions, then they may have experienced a phase transition, leading to a ferromagnetic ordering. The small magnetic field resulting from ferromagnetic ordering – if present before galaxy formation – could act as a primordial seed of the magnetic fields observed in several galaxies. Our findings suggest that the magnetization could occur in the right epoch, if the exchange boson of neutrino–neutrino interaction is a massless boson beyond the Standard Model, with a coupling constant of 2.2 × 10 − 13 ( m ν 10 − 4 eV ) 2 g 2.3 × 10 − 7 . The estimation of the magnetic seed is 2.3 × 10 − 27 G ≲ B CNB ≲ 6.8 × 10 − 10 G .
119351968
CPT/Lorentz Invariance Violation and Quantum Field Theory
Departamento de Fisica, Universidad de Santiago de ChileCasilla 307, Santiago 2, ChileE-mail: fmendez@lauca.usach.clAnalogies between the noncommutative harmonic oscillator and noncommutative ﬁelds are ana-lyzed. Following this analogywe construct examples of quantum ﬁelds theories with explicit CPTand Lorentz symmetry breaking. Some applications to baryogenesis and neutrino oscillation arealso discussed.Fifth International Conference on Mathematical Methods in Physics — IC2006April 24-28 2006Centro Brasilerio de Pesquisas Fisicas, Rio de Janeiro, Brazil
119352395
CPT / Lorentz invariance violation and neutrino oscillation
We analyze the consequences of violation of Lorentz and CPT invariance in the massless neutrino sector by deforming the canonical anti-commutation relations for the fields. We show that, for particular choices of the deformation, oscillation between massless neutrino species takes place when only Lorentz invariance is violated. On the other hand, if both Lorentz and CPT invariances are violated, we show that there is no oscillation between massless neutrino species. Comparing with the existing experimental data on neutrino oscillations, we obtain bounds on the parameter for Lorentz invariance violation.
56383156
Improving the Discovery Potential of Future Light-Shining-through-a-Wall Experiments
Planning for the next generation of light-shining-through-wall experiments has started. It is therefore timely to investigate possible ways to optimize their setups. The goals are to improve the sensitivity towards smaller couplings and increase the mass range to which the experiments are sensitive. We discuss possible magnet arrangements and the eects of the unavoidable gaps in the magnetic field profile. Furthermore, we discuss requirements on the diameter of the laser beam and aperture of the magnets in order to achieve high-quality cavities. Several well motivated extensions of the Standard Model predict the existence of very weakly