arXiv subjects
Publications and source records attributed to Beatriz Gato-Rivera.
In this article we concisely explain: what antimatter is, its differentiation between primordial and secondary, how it is produced, where it can be found, the experiments carried out at CERN to create and analyze antiatoms, the problem of the matter-antimatter asymmetry, and the medical and technological applications of antimatter in our society.
Antimatter is one of the most fascinating aspects of Particle Physics and one of the most unknown ones too. In this article we concisely explain what is antimatter and its distinction between primordial and secondary, how it is produced, where it can be found, the experiments carried out at CERN to create and analyze antiatoms, the problem of the matter-antimatter asymmetry, and the medical and technological applications of antimatter in our society. -- La antimateria es uno de los aspectos más fascinantes de la Física de Partículas, y también uno de los más desconocidos. En este artículo explicamos concisamente qué es la antimateria y su diferenciación entre primordial y secundaria, cómo se produce, donde se encuentra, los experimentos que se realizan en el CERN para crear y analizar antiátomos, el problema de la asimetría materia-antimateria, y las aplicaciones médicas y tecnológicas de la antimateria en nuestra sociedad.
A novel interpretation of the quantum mechanical superposition is put forward. Quantum systems scan all possible available states and switch randomly and very rapidly among them. The longer they remain in a given state, the larger the probability of the system to be found in that state during a measurement. A crucial property that we postulate is quantum inertia, that increases whenever a constituent is added, or the system is perturbed with all kinds of interactions. Once the quantum inertia $I_q$ reaches a critical value $I_{cr}$ for an observable, the switching among the different eigenvalues of that observable stops and the corresponding superposition comes to an end. Consequently, increasing the mass, temperature, gravitational force, etc. of a quantum system increases its quantum inertia until the superposition of states disappears for all the observables and the system transmutes into a classical one. The process could be reversible: decreasing the size, temperature, gravitational force, etc. of a classical system one could revert the situation. Entanglement can only occur between quantum systems, not between a quantum system and a classical one, because an exact synchronization between the switchings of the systems involved must be established in the first place and classical systems do not have any switchings to start with. Future experiments might determine the critical inertia $I_{cr}$ corresponding to different observables. In addition, our proposal implies a new radiation mechanism in strong gravitational fields, giving rise to non-thermal synchrotron emission, that could contribute to neutron star formation. Superconductivity, superfluidity, Bose-Einstein condensates, and any other physical phenomena at very low temperatures must be reanalyzed in the light of this interpretation, as well as mesoscopic systems in general.
Highly accurate measurements of quantum level energies in molecular systems provide a test ground for new physics, as such effects could manifest themselves as minute shifts in the quantum level structures of atoms and molecules. For the lightest molecular systems, neutral molecular hydrogen (H$_2$, HD and D$_2$) and the molecular hydrogen ions (H$_2^+$, HD$^+$ and D$_2^+$), weak force effects are several orders weaker than current experimental and theoretical results, while contributions of Newtonian gravity and the strong force at the characteristic molecular distance scale of 1 Å can be safely neglected. Comparisons between experiment and QED calculations for these molecular systems can be interpreted in terms of probing large extra space dimensions, under which gravity could become much stronger than in ordinary 3-D space. Under this assumption, using the spectra of H$_2$ we have derived constraints on the compactification scales for extra dimensions within the Arkani-Hamed-Dimopoulos-Dvali (ADD) framework, and constraints on the brane separation and bulk curvature within the Randall-Sundrum (RS-I and RS-II) frameworks.
Twenty years ago, in October 1990, I found myself attending a workshop on Theoretical Physics in Chernomorka (Ukraine) intended only for Soviet physicists. That trip to the USSR/CCCP as well as the preceding months at CERN were highly surrealistic with plenty of adventures, crucial events and anecdotes, the most amazing one involving Niels Bohr. A few months later the Soviet Union collapsed. In this article I make a personal account on the happenings of 1990, with emphasis on my incursions into the European communist world during, and also before, that year.
We introduce the `Complete Wave Function' and deduce that all living beings, not just Schroedinger's cat, are actually described by a superposition of `alive' and `dead' quantum states; otherwise they would never die. Therefore this proposal provides a quantum mechanical explanation to the world-wide observation that we all pass away. Next we consider the Measurement problem in the framework of M-theory. For this purpose, together with Schroedinger's cat we also place inside the box Rasputin's cat, which is unaffected by poison. We analyse the system identifying its excitations (catons and catinos) and we discuss its evolution: either to a classical fight or to a quantum entanglement. We also propose the $BSVΨ$ scenario, which implements the Complete Wave Function as well as the Big Bang and the String Landscape in a very (super)natural way. Then we test the gravitational decoherence of the entangled system applying an experimental setting due to Galileo. We also discuss the Information Loss paradox. For this purpose we consider a massless black cat falling inside a massive black hole. After that we outline a method to compute the contribution of black cats to the dark matter of the universe. Finally, in the spirit of Schroedinger, we propose that next generation double-slit experiments should use cats as projectiles. Cat interferometry will inevitably lead to the `Many Cats' interpretation of Quantum Mechanics, allowing to shed new light on old mysteries and paradoxes. For example, according to this interpretation, conservative estimates show that decision making of a single domestic cat will create about 550 billion whole universes every day, with as many replicas of itself.
Since 1999 it became obvious that the would be `isomorphism' between the affine $\hat sl(2)$ algebra and the N=2 superconformal algebras, proposed by some authors, simply does not work. However, this issue was never properly discussed in the literature and, as a result, some confusion still remains. In this article we finally settle down, clearly and unambiguously, the true facts: there is no isomorphism between the affine $\hat sl(2)$ algebra and the N=2 superconformal algebras.
In 1998 the Adapted Ordering Method was developed for the study of the representation theory of the superconformal algebras in two dimensions. It allows: to determine the maximal dimension for a given type of space of singular vectors, to identify all singular vectors by only a few coefficients, to spot subsingular vectors and to set the basis for constructing embedding diagrams. In this talk I introduce the present version of the Adapted Ordering Method, published in J. Phys. A: Math. Theor. 41 (2008) 045201, which can be applied to general Lie algebras and superalgebras and their generalizations, provided they can be triangulated.
In 1998 the Adapted Ordering Method was developed for the representation theory of the superconformal algebras in two dimensions. It allows: to determine maximal dimensions for a given type of space of singular vectors, to identify all singular vectors by only a few coefficients, to spot subsingular vectors and to set the basis for constructing embedding diagrams. In this article we present the Adapted Ordering Method for general Lie algebras and superalgebras, and their generalizations, provided they can be triangulated. We also review briefly the results obtained for the Virasoro algebra and for the N=2 and Ramond N=1 superconformal algebras.
I review the main features of the Dijkstra-Huiszoon-Schellekens (DHS) orientifolds and report on the search for global anomalies that Schellekens and the author have performed for these models.
The Fermi Paradox is discussed in the light of the inflationary and brane world cosmologies. We conclude that some brane world cosmologies may be of relevance for the problem of civilizations spreading across our galaxy, strengthening the Fermi Paradox, but not the inflationary cosmologies, as has been proposed.
I introduce the Fermi Paradox and some of its solutions. Then I present my own solution which includes two proposals called the Subanthropic Principle and the Undetectability Conjecture. After discussing some consequences of this solution, I make some comments about brane world scenarios and their potential to strengthen the Fermi Paradox. Finally, in the appendix I have included some questions and answers that came up during this Forum. -- En primer lugar introduzco la Paradoja de Fermi y algunas de sus soluciones. Luego presento la solucion que yo he propuesto, que incluye dos hipotesis que denomino el Principio Subantropico y la Conjetura de Indetectabilidad. Despues de discutir algunas consecuencias de esta solucion, paso a hacer algunos comentarios sobre las teorias de universos branas y su potencial para reforzar la Paradoja de Fermi. Finalmente, en el apendice incluyo algunas preguntas y respuestas que surgieron durante este Forum.
In 1998 the Adapted Ordering Method was developed for the representation theory of the superconformal algebras. This method, which proves to be very powerful, can be applied to most algebras and superalgebras, however. It allows: to determine maximal dimensions for a given type of singular vector space, to identify all singular vectors by only a few coefficients, to spot subsingular vectors and to set the basis for constructing embedding diagrams. In this article we present the Adapted Ordering Method for general algebras and superalgebras which admit a triangulation and review briefly the results obtained for the Virasoro algebra and for the N=2 and Ramond N=1 superconformal algebras.
In the recent article `Conflict between anthropic reasoning and observation'(gr-qc/0303070) Ken D. Olum, using some inflation-based ideas and the anthropic premise that we should be typical among all intelligent observers in the Universe, arrives at the puzzling conclusion that `we should find ourselves in a large civilization (of galactic size) where most observers should be, while in fact we do not'. In this note we discuss the intriguing possibility whether we could be in fact immersed in a large civilization without being aware of it. Our conclusion is that this possibility cannot be ruled out provided two conditions are met, that we call the Subanthropic Principle and the Undetectability Conjecture. ----- En el reciente articulo `Conflicto entre razonamiento antropico y observacion' Ken D. Olum, basandose en algunas ideas sobre la inflacion cosmologica y en la premisa antropica de que tenemos que ser tipicos entre los observadores inteligentes del Universo, llega a la sorprendente conclusion de que `deberiamos encontrarnos en una civilizacion grande (de tamanio galactico) al igual que la mayoria de los observadores, mientras que de hecho no lo estamos'. En este articulo discutimos la posibilidad de que nuestra civilizacion este de hecho inmersa en una civilizacion grande, sin que seamos conscientes de ello. Nuestra conclusion es que esta posibilidad no puede descartarse si se cumplen dos condiciones, que llamamos el Principio Subantropico y la Conjetura de Indetectabilidad.
This is a brief introduction to the subject of Conformal Field Theory on surfaces with boundaries and crosscaps, which describes the perturbative expansion of open string theory.
We write down one-to-one mappings between the singular vectors of the Neveu-Schwarz N=2 superconformal algebra and $16 + 16$ types of singular vectors of the Topological and of the Ramond N=2 superconformal algebras. As a result one obtains construction formulae for the latter using the construction formulae for the Neveu-Schwarz singular vectors due to Dörrzapf. The indecomposable singular vectors of the Topological and of the Ramond N=2 algebras (`no-label' and `no-helicity' singular vectors) cannot be mapped to singular vectors of the Neveu-Schwarz N=2 algebra, but to {\it subsingular} vectors, for which no construction formulae exist.
In the last six years remarkable developments have taken place concerning the representation theory of N=2 superconformal algebras. Here we present the highlights of such developments.
The Kac determinant for the Topological N=2 superconformal algebra is presented as well as a detailed analysis of the singular vectors detected by the roots of the determinants. In addition we identify the standard Verma modules containing `no-label' singular vectors (which are not detected directly by the roots of the determinants). We show that in standard Verma modules there are (at least) four different types of submodules, regarding size and shape. We also review the chiral determinant formula, for chiral Verma modules, adding new insights. Finally we transfer the results obtained to the Verma modules and singular vectors of the Ramond N=2 algebra, which have been very poorly studied so far. This work clarifies several misconceptions and confusing claims appeared in the literature about the singular vectors, Verma modules and submodules of the Topological N=2 superconformal algebra.