Search results for "JOINT"
showing 10 items of 1472 documents
A non self-adjoint model on a two dimensional noncommutative space with unbound metric
2013
We demonstrate that a non self-adjoint Hamiltonian of harmonic oscillator type defined on a two-dimensional noncommutative space can be diagonalized exactly by making use of pseudo-bosonic operators. The model admits an antilinear symmetry and is of the type studied in the context of PT-symmetric quantum mechanics. Its eigenvalues are computed to be real for the entire range of the coupling constants and the biorthogonal sets of eigenstates for the Hamiltonian and its adjoint are explicitly constructed. We show that despite the fact that these sets are complete and biorthogonal, they involve an unbounded metric operator and therefore do not constitute (Riesz) bases for the Hilbert space $\L…
Combinatorics of theSU(2)black hole entropy in loop quantum gravity
2009
We use the combinatorial and number-theoretical methods developed in previous works by the authors to study black hole entropy in the new proposal put forth by Engle, Noui, and Perez. Specifically, we give the generating functions relevant for the computation of the entropy and use them to derive its asymptotic behavior, including the value of the Immirzi parameter and the coefficient of the logarithmic correction.
Weakly interacting dark matter particle of a minimal technicolor theory
2007
We consider the possibility that a massive fourth family neutrino, predicted by a recently proposed minimal technicolor theory, could be the source of the dark matter in the Universe. The model has two techniflavors in the adjoint representation of a SU(2) techicolor gauge group and its consistency requires the existence of a fourth family of leptons. By a suitable hypercharge assignment the techniquarks together with the new leptons look like a conventional fourth standard model family. We show that the new (Majorana) neutrino N can be the dark matter particle if m{sub N}{approx}100-500 GeV and the expansion rate of the Universe at early times is dominated by an energy component scaling as…
Accurate modeling of weak lensing with the stochastic gravitational lensing method
2011
We revise and extend the stochastic gravitational lensing method (the sGL method) first introduced by Kainulainen and Marra [Phys. Rev. D 80, 123020 (2009)]. Here we include a realistic halo-mass function and density profiles to model the distribution of mass between and within galaxies, galaxy groups, and galaxy clusters. We also introduce a modeling of the filamentary large-scale structures and a method to embed halos into these structures. We show that the sGL method naturally reproduces the weak lensing results for the Millennium simulation. The strength of the sGL method is that a numerical code based on it can compute the lensing probability distribution function (PDF) for a given inh…
Monte Carlo techniques in small-x physics: Formal studies and phenomenology
2013
We discuss the solution to the BFKL equation in the adjoint representation at LO and NLO accuracy for the N = 4 SUSY theory. We use Monte Carlo techniques to study numerically the Gluon Green’s function at LO and NLO directly written in the transverse momentum space which allows for the factorization of its infrared divergencies. Finally, we discuss the applicability of our approach to phenomenological searches for the BKP Odderon at the LHC.
Measurements of charm mixing and CP violation using D0→K±π∓ decays
2017
Measurements of charm mixing and CP violation parameters from the decay-time-dependent ratio of D0→K+π− to D0→K−π+ decay rates and the charge-conjugate ratio are reported. The analysis uses B¯¯¯¯→D∗+μ−X, and charge-conjugate decays, where D∗+→D0π+, and D0→K∓π±. The pp collision data are recorded by the LHCb experiment at center-of-mass energies s√ = 7 and 8 TeV, corresponding to an integrated luminosity of 3 fb−1. The data are analyzed under three hypotheses: (i) mixing assuming CP symmetry, (ii) mixing assuming no direct CP violation in the Cabibbo-favored or doubly Cabibbo-suppressed decay amplitudes, and (iii) mixing allowing either direct CP violation and/or CP violation in the superpos…
From self-adjoint to non self-adjoint harmonic oscillators: physical consequences and mathematical pitfalls
2013
Using as a prototype example the harmonic oscillator we show how losing self-adjointness of the hamiltonian $H$ changes drastically the related functional structure. In particular, we show that even a small deviation from strict self-adjointness of $H$ produces two deep consequences, not well understood in the literature: first of all, the original orthonormal basis of $H$ splits into two families of biorthogonal vectors. These two families are complete but, contrarily to what often claimed for similar systems, none of them is a basis for the Hilbert space $\Hil$. Secondly, the so-called metric operator is unbounded, as well as its inverse. In the second part of the paper, after an extensio…
The Joint SLR (Optical Range) and Radar-VLBI Satellite Observations using VIRAC Radio Telescope RT32, RT16 and SLR Station Riga
2020
Abstract Joint VLBI and SLR satellite tracking is a novel tracking approach to explore potential applications and to work out common procedures to coordinate observations between astronomical observatories in Latvia. Global Navigation Satellite System (GNSS) satellites equipped with laser retroreflectors have been chosen as test targets because they are accessible by both measuring techniques – satellite laser ranging (SLR) and Very Long Base Interferometry (VLBI). The first Joint SLR and VLBI observations of selected GNSS satellites using three of Latvian large-scale astronomical utilities – VIRAC radio telescopes RT32 and RT16 (Ventspils International Radio Astronomy Centre of Ventspils U…
Susy for non-Hermitian Hamiltonians, with a view to coherent states
2020
We propose an extended version of supersymmetric quantum mechanics which can be useful if the Hamiltonian of the physical system under investigation is not Hermitian. The method is based on the use of two, in general different, superpotentials. Bi-coherent states of the Gazeau-Klauder type are constructed and their properties are analyzed. Some examples are also discussed, including an application to the Black-Scholes equation, one of the most important equations in Finance.
No-Forcing and No-Matching Theorems for Classical Probability Applied to Quantum Mechanics
2013
Correlations of spins in a system of entangled particles are inconsistent with Kolmogorov's probability theory (KPT), provided the system is assumed to be non-contextual. In the Alice-Bob EPR paradigm, non-contextuality means that the identity of Alice's spin (i.e., the probability space on which it is defined as a random variable) is determined only by the axis \alphai chosen by Alice, irrespective of Bob's axis \betaj (and vice versa). Here, we study contextual KPT models, with two properties: (1) Alice's and Bob's spins are identified as Aij and Bij, even though their distributions are determined by, respectively, \alphai alone and \betaj alone, in accordance with the no-signaling requir…