242 research outputs found
Contractions of low-dimensional nilpotent Jordan algebras
In this paper we classify the laws of three-dimensional and four-dimensional
nilpotent Jordan algebras over the field of complex numbers. We describe the
irreducible components of their algebraic varieties and extend contractions and
deformations among them. In particular, we prove that J2 and J3 are irreducible
and that J4 is the union of the Zariski closures of two rigid Jordan algebras.Comment: 12 pages, 3 figure
Violation of a Bell inequality in particle physics experimentally verified?
Relevant aspects for testing Bell inequalities with entangled meson-antimeson
systems are analyzed. In particular, we argue that the result of A. Go, J. Mod.
Optics 51, 991 (2004), which nicely illustrate the quantum entanglement of
B-meson pairs, cannot be considered as a Bell-test refuting local realism.Comment: 9 page
Shallow structure beneath the Central Volcanic Complex of Tenerife from new gravity data: implications for its evolution and recent reactivation
We present a new local Bouguer anomaly map of the Central Volcanic Complex (CVC) of Tenerife, Spain, constructed from the amalgamation of 323 new high precision gravity measurements with existing gravity data from 361 observations. The new anomaly map images the high-density core of the CVC and the pronounced gravity low centred in the Las Cañadas caldera in greater detail than previously available. Mathematical construction of a sub-surface model from the local anomaly data, employing a 3D inversion based on 'growing' the sub-surface density distribution via the aggregation of cells, enables mapping of the shallow structure beneath the complex, giving unprecedented insights into the sub-surface architecture. We find the resultant density distribution in agreement with geological and other geophysical data. The modelled sub-surface structure supports a vertical collapse origin of the caldera, and maps the headwall of the ca. 180 ka Icod landslide, which appears to lie buried beneath the Pico Viejo–Pico Teide stratovolcanic complex. The results allow us to put into context the recorded ground deformation and gravity changes at the CVC during its reactivation in spring 2004 in relation to its dominant structural building blocks. For example, the areas undergoing the most significant changes at depth in recent years are underlain by low-density material and are aligned along long-standing structural entities, which have shaped this volcanic ocean island over the past few million years
On the structure of maximal solvable extensions and of Levi extensions of nilpotent algebras
We establish an improved upper estimate on dimension of any solvable algebra
s with its nilradical isomorphic to a given nilpotent Lie algebra n. Next we
consider Levi decomposable algebras with a given nilradical n and investigate
restrictions on possible Levi factors originating from the structure of
characteristic ideals of n. We present a new perspective on Turkowski's
classification of Levi decomposable algebras up to dimension 9.Comment: 21 pages; major revision - one section added, another erased;
author's version of the published pape
An open quantum system approach to EPR correlations in K0-K0 system
We find the time evolution of the system of two non-interacting unstable
particles, distinguishable as well as identical ones, in arbitrary reference
frame having only the Kraus operators governing the evolution of its components
in the rest frame. We than calculate in the rigorous way
Einstein-Podolsky-Rosen quantum correlation functions for K0-K0 system in the
singlet state taking into account CP-violation and decoherence and show that
the results are exactly the same despite the fact we treat kaons as
distinguishable or identical particles which means that the statistics of the
particles plays no role, at least in considered cases.Comment: 14 pp. no fig
Invariants of solvable rigid Lie algebras up to dimension 8
The invariants of all complex solvable rigid Lie algebras up to dimension
eight are computed. Moreover we show, for rank one solvable algebras, some
criteria to deduce to non-existence of non-trivial invariants or the existence
of fundamental sets of invariants formed by rational functions of the Casimir
invariants of the associated nilradical.Comment: 16 pages, 7 table
All solvable extensions of a class of nilpotent Lie algebras of dimension n and degree of nilpotency n-1
We construct all solvable Lie algebras with a specific n-dimensional
nilradical n_(n,2) (of degree of nilpotency (n-1) and with an (n-2)-dimensional
maximal Abelian ideal). We find that for given n such a solvable algebra is
unique up to isomorphisms. Using the method of moving frames we construct a
basis for the Casimir invariants of the nilradical n_(n,2). We also construct a
basis for the generalized Casimir invariants of its solvable extension s_(n+1)
consisting entirely of rational functions of the chosen invariants of the
nilradical.Comment: 19 pages; added references, changes mainly in introduction and
conclusions, typos corrected; submitted to J. Phys. A, version to be
publishe
Bell-inequalities for Pairs from -Resonance Decays
We analyze the premises of recent propositions to test local realism via
Bell-inequalities using neutral kaons from -resonance decays as entangled
EPR-pairs. We pay special attention to the derivation of Bell-inequalities, or
related expressions, for unstable and oscillating kaon `quasi-spin' states and
to the possibility of the actual identification of these states through their
associated decay modes. We discuss an indirect method to extract probabilities
to find these states by combining experimental information with theoretical
input. However, we still find inconsistencies in previous derivations of
Bell-inequalities. We show that the identification of the quasi-spin states via
their associated decay mode does not allow the free choice to perform different
tests on them, a property which is crucial to establish the validity of any
Bell-inequality in the context of local realism. In view of this we propose a
different kind of Bell-inequality in which the free choice or adjustability of
the experimental set-up is guaranteed. We also show that the proposed
inequalities are violated by quantum mechanics.Comment: 22 pages. Late
Space-Dependent Probabilities for Oscillations
We analyze oscillations in space in terms of propagating wave
packets with coherent and components. The oscillation probabilities
and depending only on the
distance , are defined through the time integration of a current density
. The definition is such that it coincides with the experimental
setting, thus avoiding some ambiguities and clarifying some controversies that
have been discussed recently.Comment: 11 pages, late
Three-party entanglement from positronium
The decay of ortho-positronium into three photons produces a physical
realization of a pure state with three-party entanglement. Its quantum
correlations are analyzed using recent results on quantum information theory,
looking for the final state which has the maximal amount of GHZ-like
correlations. This state allows for a statistical dismissal of local realism
stronger than the one obtained using any entangled state of two spin one-half
particles.Comment: REVTEX, 13 pages, 3 figure
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