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Author Asenjo, F.A.; Comisso, L.
Title Gravitational electromotive force in magnetic reconnection around Schwarzschild black holes Type
Year 2019 Publication Physical Review D Abbreviated Journal (up) Phys. Rev. D
Volume 99 Issue 6 Pages 7 pp
Keywords
Abstract We analytically explore the effects of the gravitational electromotive force on magnetic reconnection around Schwarzschild black holes through a generalized general-relativistic magnetohydrodynamic model that retains two-fluid effects. It is shown that the gravitational electromotive force can couple to collisionless two-fluid effects and drive magnetic reconnection. This is allowed by the departure from quasineutrality in curved spacetime, which is explicitly manifested as the emergence of an effective resistivity in Ohm's law. The departure from quasineutrality is owed to different gravitational pulls experienced by separate parts of the current layer. This produces an enhancement of the reconnecion rate due to purely gravitational effects.
Address [Asenjo, Felipe A.] Univ Adolfo Ibanez, Fac Ingn & Ciencias, Santiago 7941169, Chile, Email: felipe.asenjo@uai.cl;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000462917900001 Approved
Call Number UAI @ eduardo.moreno @ Serial 993
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Author Asenjo, F.A.; Mahajan, S.M.
Title Resonant interaction between dispersive gravitational waves and scalar massive particles Type
Year 2020 Publication Physical Review D Abbreviated Journal (up) Phys. Rev. D
Volume 101 Issue 6 Pages 4 pp
Keywords
Abstract The Klein-Gordon equation is solved in the curved background spacetime created by a dispersive gravitational wave. Unlike solutions of perturbed Einstein equations in vacuum, dispersive gravitational waves do not travel exactly at the speed of light. As a consequence, the gravitational wave can resonantly exchange energy with scalar massive particles. Some details of the resonant interaction are displayed in a calculation demonstrating how relativistic particles (modeled by the Klein-Gordon equation), feeding on such gravitational waves, may be driven to extreme energies.
Address [Asenjo, Felipe A.] Univ Adolfo Ibanez, Fac Ingn & Ciencias, Santiago 7941169, Chile, Email: felipe.asenjo@uai.cl;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000518819200001 Approved
Call Number UAI @ eduardo.moreno @ Serial 1160
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Author Comisso, L.; Asenjo, F.A.
Title Generalized magnetofluid connections in a curved spacetime Type
Year 2020 Publication Physical Review D Abbreviated Journal (up) Phys. Rev. D
Volume 102 Issue 2 Pages 8 pp
Keywords
Abstract The ideal magnetohydrodynamic theorem on the conservation of the magnetic connections between plasma elements is extended to nonideal relativistic plasmas in curved spacetime. The existence of generalized magnetofluid connections that are preserved by the plasma dynamics is formalized by means of a covariant connection equation that includes different nonideal effects. These generalized connections are constituted by 2-dimensional hypersurfaces, which are linked to an antisymmetric tensor field that unifies the electromagnetic and fluid fields. They can be interpreted in terms of generalized magnetofluid vorticity field lines by considering a 3 + 1 foliation of spacetime and a time resetting projection that compensates for the loss of simultaneity between spatially separated events. The worldshects of the generalized magnetofluid vorticity field lines play a fundamental role in the plasma dynamics by prohibiting evolutions that do not preserve the magnetofluid connectivity.
Address [Comisso, Luca] Columbia Univ, Dept Astron, New York, NY 10027 USA, Email: luca.comisso@columbia.edu;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000552579500002 Approved
Call Number UAI @ eduardo.moreno @ Serial 1212
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Author Comisso, L.; Asenjo, F.A.
Title Magnetic reconnection as a mechanism for energy extraction from rotating black holes Type
Year 2021 Publication Physical Review D Abbreviated Journal (up) Phys. Rev. D.
Volume 103 Issue 2 Pages 023014
Keywords BLANDFORD-ZNAJEK MECHANISM; NEAR-INFRARED FLARES; SIMULATIONS; JETS; DRIVEN
Abstract Spinning black holes store rotational energy that can be extracted. When a black hole is immersed in an externally supplied magnetic field, reconnection of magnetic field lines within the ergosphere can generate negative energy (relative to infinity) particles that fall into the black hole event horizon while the other accelerated particles escape stealing energy from the black hole. We show analytically that energy extraction via magnetic reconnection is possible when the black hole spin is high (dimensionless spin a similar to 1) and the plasma is strongly magnetized (plasma magnetization sigma(0) > 1/3). The parameter space region where energy extraction is allowed depends on the plasma magnetization and the orientation of the reconnecting magnetic field lines. For sigma(0) >> 1, the asymptotic negative energy at infinity per enthalpy of the decelerated plasma that is swallowed by a maximally rotating black hole is found to be epsilon(infinity)(-) similar or equal to – root sigma(0)/3. The accelerated plasma that escapes to infinity and takes away black hole energy asymptotes the energy at infinity per enthalpy epsilon(infinity)(+) similar or equal to root 3 sigma(0).. We show that the maximum power extracted from the black hole by the escaping plasma is P-extr(max) similar to 0.1M(2) root sigma(0)w(0) (here, M is the black hole mass and w(0) is the plasma enthalpy density) for the collisionless plasma regime and one order of magnitude lower for the collisional regime. Energy extraction causes a significant spindown of the black hole when a similar to 1. The maximum efficiency of the plasma energization process via magnetic reconnection in the ergosphere is found to be eta(max) similar or equal to 3/2. Since fast magnetic reconnection in the ergosphere should occur intermittently in the scenario proposed here, the associated emission within a few gravitational radii from the black hole is expected to display a bursty nature.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000607513600001 Approved
Call Number UAI @ alexi.delcanto @ Serial 1323
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Author Ekman, R.; Asenjo, F.A.; Zamanian, J.
Title Relativistic kinetic equation for spin-1/2 particles in the long-scale-length approximation Type
Year 2017 Publication Physical Review E Abbreviated Journal (up) Phys. Rev. E
Volume 96 Issue 2 Pages 8 pp
Keywords
Abstract In this paper, we derive a fully relativistic kinetic theory for spin-1/2 particles and its coupling to Maxwell's equations, valid in the long-scale-length limit, where the fields vary on a scale much longer than the localization of the particles; we work to first order in (h) over bar. Our starting point is a Foldy-Wouthuysen (FW) transformation, applicable to this regime, of the Dirac Hamiltonian. We derive the corresponding evolution equation for the Wigner quasidistribution in an external electromagnetic field. Using a Lagrangian method we find expressions for the charge and current densities, expressed as free and bound parts. It is furthermore found that the velocity is nontrivially related to the momentum variable, with the difference depending on the spin and the external electromagnetic fields. This fact that has previously been discussed as “hidden momentum” and is due to that the FW transformation maps pointlike particles to particle clouds for which the prescription of minimal coupling is incorrect, as they have multipole moments. We express energy and momentum conservation for the system of particles and the electromagnetic field, and discuss our results in the context of the Abraham-Minkowski dilemma.
Address [Ekman, R.; Zamanian, J.] Umea Univ, Dept Phys, SE-90187 Umea, Sweden
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2470-0045 ISBN Medium
Area Expedition Conference
Notes WOS:000408118100012 Approved
Call Number UAI @ eduardo.moreno @ Serial 759
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Author Asenjo, F.A.; Mahajan, S.M.
Title Diamagnetic field states in cosmological plasmas Type
Year 2019 Publication Physical Review E Abbreviated Journal (up) Phys. Rev. E
Volume 99 Issue 5 Pages 7 pp
Keywords
Abstract Using a generally covariant electrovortic (magnetofluid) formalism for relativistic plasmas, the dynamical evolution of a generalized vorticity (a combination of the magnetic and kinematic parts) is studied in a cosmological context. We derive macroscopic vorticity and magnetic field structures that can emerge in spatial equilibrium configurations of the relativistic plasma. These fields, however, evolve in time. These magnetic and velocity fields, self-consistently sustained in a plasma with arbitrary thermodynamics, constitute a diamagnetic state in the expanding universe. In particular, we explore a special class of magnetic and velocity field structures supported by a plasma in which the generalized vorticity vanishes. We derive a highly interesting characteristic of such “superconductor-like” fields in a cosmological plasmas in the radiation era in the early universe. In that case, the fields grow proportional to the scale factor, establishing a deep connection between the expanding universe and the primordial magnetic fields.
Address [Asenjo, Felipe A.] Univ Adolfo Ibanez, Fac Ingn & Ciencias, Santiago 7941169, Chile, Email: felipe.asenjo@uai.cl;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2470-0045 ISBN Medium
Area Expedition Conference
Notes WOS:000467737500016 Approved
Call Number UAI @ eduardo.moreno @ Serial 999
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Author Comisso, L.; Asenjo, F.A.
Title Thermal-Inertial Effects on Magnetic Reconnection in Relativistic Pair Plasmas Type
Year 2014 Publication Physical Review Letters Abbreviated Journal (up) Phys. Rev. Lett.
Volume 113 Issue 4 Pages 5 pp
Keywords
Abstract The magnetic reconnection process is studied in relativistic pair plasmas when the thermal and inertial properties of the magnetohydrodynamical fluid are included. We find that in both Sweet-Parker and Petschek relativistic scenarios there is an increase of the reconnection rate owing to the thermal-inertial effects, both satisfying causality. To characterize the new effects we define a thermal-inertial number which is independent of the relativistic Lundquist number, implying that reconnection can be achieved even for vanishing resistivity as a result of only thermal-inertial effects. The current model has fundamental importance for relativistic collisionless reconnection, as it constitutes the simplest way to get reconnection rates faster than those accessible with the sole resistivity.
Address [Comisso, Luca] Politecn Torino, Dipartimento Energia, I-10129 Turin, Italy, Email: luca.comisso@polito.it;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:000339620300007 Approved
Call Number UAI @ eduardo.moreno @ Serial 393
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Author Braun, S.; Asenjo, F.A.; Mahajan, S.M.
Title Comment on “Spin-Gradient-Driven Light Amplification in a Quantum Plasma” Reply Type
Year 2014 Publication Physical Review Letters Abbreviated Journal (up) Phys. Rev. Lett.
Volume 112 Issue 12 Pages 1 pp
Keywords
Abstract
Address [Braun, S.; Asenjo, F. A.; Mahajan, S. M.] Univ Texas AustinStudies, Inst Fus Studies, Austin, TX 78712 USA, Email: faz@physics.utexas.edu;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:000333921000007 Approved
Call Number UAI @ eduardo.moreno @ Serial 471
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Author Asenjo, F.A.; Comisso, L.
Title Generalized Magnetofluid Connections in Relativistic Magnetohydrodynamics Type
Year 2015 Publication Physical Review Letters Abbreviated Journal (up) Phys. Rev. Lett.
Volume 114 Issue 11 Pages 5 pp
Keywords
Abstract The concept of magnetic connections is extended to nonideal relativistic magnetohydrodynamical plasmas. Adopting a general set of equations for relativistic magnetohydrodynamics including thermal-inertial, thermal electromotive, Hall, and current-inertia effects, we derive a new covariant connection equation showing the existence of generalized magnetofluid connections that are preserved during the dissipationless plasma dynamics. These connections are intimately linked to a general antisymmetric tensor that unifies the electromagnetic and fluid fields, allowing the extension of the magnetic connection notion to a much broader concept.
Address [Asenjo, Felipe A.] Univ Adolfo Ibanez, Fac Ingn & Ciencias, Santiago 7941169, Chile, Email: felipe.asenjo@uai.cl;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:000351507400011 Approved
Call Number UAI @ eduardo.moreno @ Serial 478
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Author Asenjo, F.A.; Comisso, L.
Title Relativistic Magnetic Reconnection in Kerr Spacetime Type
Year 2017 Publication Physical Review Letters Abbreviated Journal (up) Phys. Rev. Lett.
Volume 118 Issue 5 Pages 5 pp
Keywords
Abstract The magnetic reconnection process is analyzed for relativistic magnetohydrodynamical plasmas around rotating black holes. A simple generalization of the Sweet-Parker model is used as a first approximation to the problem. The reconnection rate, as well as other important properties of the reconnection layer, has been calculated taking into account the effect of spacetime curvature. Azimuthal and radial current sheet configurations in the equatorial plane of the black hole have been studied, and the case of small black hole rotation rate has been analyzed. For the azimuthal configuration, it is found that the black hole rotation decreases the reconnection rate. On the other hand, in the radial configuration, it is the gravitational force created by the black hole mass that decreases the reconnection rate. These results establish a fundamental interaction between gravity and magnetic reconnection in astrophysical contexts.
Address [Asenjo, Felipe A.] Univ Adolfo Ibanez, Fac Ingn & Ciencias, Santiago 7941169, Chile, Email: felipe.asenjo@uai.cl;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:000396415100005 Approved
Call Number UAI @ eduardo.moreno @ Serial 702
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Author Qadir, A.; Asenjo, F.A.; Mahajan, S.M.
Title Magnetic field seed generation in plasmas around charged and rotating black holes Type
Year 2014 Publication Physica Scripta Abbreviated Journal (up) Phys. Scr.
Volume 89 Issue 8 Pages 7 pp
Keywords seed magnetic field; general relativistic drive; Kerr metric
Abstract Previous work by the authors introduced the possibility of generating seed magnetic fields by spacetime curvature and applied it in the vicinity of a Schwarzschild black hole. It was pointed out that it would be worthwhile to consider the effect in other background geometries and particularly in the vicinity of a rotating black hole, which is generically to be expected, astrophysically. In this paper that suggestion is followed up and we calculate generated magnetic field seed due to Reissner-Nordstrom and Kerr spacetimes. The conditions for the drive for the seed of a magnetic field is obtained for charged black holes, finding that in the horizon the drive vanishes. Also, the psi N-force produced by the Kerr black hole is obtained and its relation with the magnetic field seed is discussed, producing a more effective drive.
Address [Qadir, Asghar] Natl Univ Sci & Technol, Ctr Adv Math & Phys, Islamabad 4400, Pakistan, Email: aqadirmath@yahoo.com
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-8949 ISBN Medium
Area Expedition Conference
Notes WOS:000343295000004 Approved
Call Number UAI @ eduardo.moreno @ Serial 469
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Author Asenjo, F.A.; Mahajan, S.M.
Title Relativistic quantum vorticity of the quadratic form of the Dirac equation Type
Year 2015 Publication Physica Scripta Abbreviated Journal (up) Phys. Scr.
Volume 90 Issue 1 Pages 4 pp
Keywords relativistic quantum mechanics; hydrodynamical version; Feynman-GellMann equation
Abstract We explore the fluid version of the quadratic form of the Dirac equation, sometimes called the Feynman-Gell-Mann equation. The dynamics of the quantum spinor field is represented by equations of motion for the fluid density, the velocity field, and the spin field. In analogy with classical relativistic and non-relativistic quantum theories, the fully relativistic fluid formulation of this equation allows a vortex dynamics. The vortical form is described by a total tensor field that is the weighted combination of the inertial, electromagnetic and quantum forces. The dynamics contrives the quadratic form of the Dirac equation as a total vorticity free system.
Address [Asenjo, Felipe A.] Univ Adolfo Ibanez, Fac Ingn & Ciencias, Santiago, Chile, Email: felipe.asenjo@uai.cl
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-8949 ISBN Medium
Area Expedition Conference
Notes WOS:000349301500001 Approved
Call Number UAI @ eduardo.moreno @ Serial 458
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Author Hojman, S.A.; Asenjo, F.A.
Title Classical and Quantum Dispersion Relations Type
Year 2020 Publication Physica Scripta Abbreviated Journal (up) Phys. Scr.
Volume 95 Issue 8 Pages 7 pp
Keywords Quantum Hamilton-Jacobi equation; Bohm potential; dispersion relation
Abstract It is showed that, in general, classical and quantum dispersion relations are different due to the presence of the Bohm potential. There are exact particular solutions of the quantum (wave) theory which obey the classical dispersion relation, but they differ in the general case. The dispersion relations may also coincide when additional assumptions are made, such as WKB or eikonal approximations, for instance. This general result also holds for non-quantum wave equations derived from classical counterparts, such as in ray and wave optics, for instance. Explicit examples are given for covariant scalar, vectorial and tensorial fields in flat and curved spacetimes.
Address [Hojman, Sergio A.] Univ Adolfo Ibanez, Fac Artes Liberales, Dept Ciencias, Santiago 7491169, Chile, Email: sergio.hojman@uai.cl;
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-8949 ISBN Medium
Area Expedition Conference
Notes WOS:000543208700001 Approved
Call Number UAI @ eduardo.moreno @ Serial 1184
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Author Hojman, S.J.; Moya-Cessa, H.M.; Soto-Eguibar, F.; Asenjo, F.A.
Title Time-dependent harmonic oscillators and SUSY in time domain Type
Year 2021 Publication Physica Scripta Abbreviated Journal (up) Phys. Scr.
Volume 96 Issue 12 Pages 125218
Keywords time domain super-symmetry; time dependent harmonic oscillator; Bohm potential; Ermakov-lewis invariant
Abstract We show that the time-dependent harmonic oscillator has a repulsive or inverted oscillator as a time domain SUSY-like partner. Examples of several kinds of super-symmetrical time dependent frequency systems are presented.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-8949 ISBN Medium
Area Expedition Conference
Notes WOS:000698808000001 Approved
Call Number UAI @ alexi.delcanto @ Serial 1467
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Author Caerols, H.; Asenjo, F.A.
Title Estimating the Moon-to-Earth Radius Ratio with a Smartphone, a Telescope, and an Eclipse Type
Year 2020 Publication Physics Teacher Abbreviated Journal (up) Phys. Teach.
Volume 58 Issue 7 Pages 497-501
Keywords
Abstract From ancient times, the different features of planets and moons have created a huge interest. Aristarchus was one of the first to study the relative relations among Earth, Moon, and Sun. This interest has remained until today, and therefore it is always relevant to make this knowledge more appealing to the younger generations. Nowadays, smartphone technology has become an important tool to teach physics, and this gives us a huge opportunity to bring science closer to students in a simpler manner. In this work, we show how simple photographs of a partial lunar eclipse are sufficiently good to estimate the ratio between the Moon and Earth radii. After taking the photographs, the procedure for the calculation is straightforward and it can be reproduced easily in a one–hour class
Address [Caerols, Hugo; Asenjo, Felipe A.] Univ Adolfo Ibanez, Fac Ingn & Ciencias, Santiago, Chile, Email: felipe.asenjo@uai.cl
Corporate Author Thesis
Publisher Amer Assn Physics Teachers Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0031-921x ISBN Medium
Area Expedition Conference
Notes WOS:000576343700015 Approved
Call Number UAI @ alexi.delcanto @ Serial 1234
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Author Rubio, C.A.; Asenjo, F.A.; Hojman, S.A.
Title Quantum Cosmologies Under Geometrical Unification of Gravity and Dark Energy Type
Year 2019 Publication Symmetry-Basel Abbreviated Journal (up) Symmetry
Volume 11 Issue 7 Pages
Keywords
Abstract A Friedmann-Robertson-Walker Universe was studied with a dark energy component represented by a quintessence field. The Lagrangian for this system, hereafter called the Friedmann-Robertson-Walker-quintessence (FRWq) system, was presented. It was shown that the classical Lagrangian reproduces the usual two (second order) dynamical equations for the radius of the Universe and for the quintessence scalar field, as well as a (first order) constraint equation. Our approach naturally unified gravity and dark energy, as it was obtained that the Lagrangian and the equations of motion are those of a relativistic particle moving on a two-dimensional, conformally flat spacetime. The conformal metric factor was related to the dark energy scalar field potential. We proceeded to quantize the system in three different schemes. First, we assumed the Universe was a spinless particle (as it is common in literature), obtaining a quantum theory for a Universe described by the Klein-Gordon equation. Second, we pushed the quantization scheme further, assuming the Universe as a Dirac particle, and therefore constructing its corresponding Dirac and Majorana theories. With the different theories, we calculated the expected values for the scale factor of the Universe. They depend on the type of quantization scheme used. The differences between the Dirac and Majorana schemes are highlighted here. The implications of the different quantization procedures are discussed. Finally, the possible consequences for a multiverse theory of the Dirac and Majorana quantized Universe are briefly considered.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2073-8994 ISBN Medium
Area Expedition Conference
Notes WOS:000481979000025 Approved
Call Number UAI @ eduardo.moreno @ Serial 1048
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