Papers by Spyros Konitopoulos
Fortschritte der Physik, Nov 10, 2023
In the gauge theoretic approach of gravity, General Relativity is described by gauging the symmet... more In the gauge theoretic approach of gravity, General Relativity is described by gauging the symmetry of the tangent manifold in four dimensions. Usually the dimension of the tangent space is considered to be equal to the dimension of the curved manifold. However, the tangent group of a manifold of dimension d is not necessarily SO(d). It has been suggested earlier that by gauging an enlarged symmetry of the tangent space in four dimensions one could unify gravity with internal interactions. Here we consider such a unified model by gauging the SO (1,17) as the extended Lorentz group overcoming in this way some difficulties of the previous attempts of similar unification and eventually we obtain the SO(10) GUT, supplemented by an SU(2)×SU(2) global symmetry.
Phys. Rev. D 104, 064018, 2021, Apr 16, 2021
In this work we present the foundations of generalized scalar-tensor theories arising from vector... more In this work we present the foundations of generalized scalar-tensor theories arising from vector bundle constructions, and we study the kinematic, dynamical and cosmological consequences. In particular, over a pseudo-Riemannian space-time base manifold, we define a fiber structure with two scalar fields. The resulting space is a 6-dimensional vector bundle endowed with a non-linear connection. We provide the form of the geodesics and the Raychaudhuri and general field equations, both in Palatini and metrical method. When applied at a cosmological framework, this novel geometrical structure induces extra terms in the modified Friedmann equations, leading to the appearance of an effective dark energy sector, as well as of an interaction of the dark mater sector with the metric. We show that we can obtain the standard thermal history of the universe, with the sequence of matter and dark-energy epochs, and furthermore the effective dark-energy equation-of-state parameter can lie in the...
Nuclear Physics B, 2021
A systematic method is presented for the construction and classification of algebras of gauge tra... more A systematic method is presented for the construction and classification of algebras of gauge transformations for arbitrary high rank tensor gauge fields. For any tensor gauge field of a given rank, the gauge transformation will be stated, in a generic way, via an ansatz that contains all the possible terms, with arbitrary coefficients and the maximum number of tensor gauge functions. Although the requirement for the closure of the algebra will prove to be restrictive, a variety of legitimate choices remains. Adjusting properly the values of the initial coefficients and imposing restrictions on the gauge functions, one can, on the one hand, recover the so far analysed algebras and on the other, construct new ones. The presentation of a new algebra for tensor gauge transformations is the central result of this article.
arXiv: 1804.01563, Apr 3, 2018
We define two a priori tests of pseudo-random number generators for the class of linear matrix-re... more We define two a priori tests of pseudo-random number generators for the class of linear matrix-recursions. The first desirable property of a random number generator is the smallness of serial or lagged correlations between generated numbers. For the particular matrix generator called MIXMAX, we find that the serial correlation actually vanishes. Next, we define a more sophisticated measure of correlation, which is a multiple correlator between elements of the generated vectors. The second desirable property for a linear generator is the favorable structure of the lattice which typically appears in dimensions higher than the dimension of the phase space of the generator, as discovered by Marsaglia. We define an appropriate generalization of the notion of the spectral index for LCG which is a measure of goodness of this lattice to the matrix generators such as MIXMAX.
EPJ Web of Conferences 125, 04016 (2016), Oct 28, 2016
We assume that inside the hadrons there are additional partons - tensorgluons - which carry the s... more We assume that inside the hadrons there are additional partons - tensorgluons - which carry the same charges as the gluons, but have larger spin. That assumption leads to a possible contribution of polarised tensorgluon density to the spin of the nucleon. The nonzero density of tensorgluons can be created inside a nucleon by radiation of tensorgluons by gluons. Tensorgluons can carry a part of nucleon momentum together with gluons. Because tensorgluons have a larger spin, they can influence the spin structure of the nucleon. This contribution appears in the next to leading order, compared to the gluons and can provide a substantial screening effect due to the larger spin of tensorgluons.
J. Math. Phys. 55, 062304 (2014), Jun 10, 2014
We investigate metric independent, gauge invariant and closed forms in the generalized YM theory.... more We investigate metric independent, gauge invariant and closed forms in the generalized YM theory. These forms are polynomial on the corresponding fields strength tensors - curvature forms and are analogous to the Pontryagin-Chern densities in the YM gauge theory. The corresponding secondary characteristic classes have been expressed in integral form in analogy with the Chern-Simons form. Because they are not unique, the secondary forms can be dramatically simplified by the addition of properly chosen differentials of one-step-lower-order forms. Their gauge variation can also be found yielding the potential anomalies in the gauge field theory.
EPL, 85 (2009) 51001, Mar 16, 2009
We considered spin-two gauge boson production in the fermion pair annihilation process and calcul... more We considered spin-two gauge boson production in the fermion pair annihilation process and calculated the polarized cross-sections for each set of helicity orientations of initial and final particles. Adding up all sixteen amplitudes and averaging over the initial particle spins, we obtained the unpolarized cross-section. The angular dependence of these cross-sections is compared with the similar annihilation cross-sections in QED with two photons in the final state, with two gluons in QCD and W-pair in the electroweak theory.
J. Phys. A: Math. Theor. 41 (2008) 355402 (17pp), Jul 29, 2008
In the non-Abelian tensor gauge field theory a lower-rank field is represented by a general nonsy... more In the non-Abelian tensor gauge field theory a lower-rank field is represented by a general nonsymmetric tensor and describes the propagation of charged bosons of helicities two and zero. We clarify and prove this result from different perspectives which would include generalized Bianchi identities and the analysis of the corresponding partial differential equation. We suggest a new method for counting propagating modes in general gauge field theories. We derive also the expression for the energy–momentum tensor and confirm that its nonzero components get contribution only from helicity-two and helicityzero states. We extended this analysis considering the interaction between two currents caused by the exchange of a tensor gauge field and proved that the residue at the pole is the sum of three terms each of which describes positive norm polarizations of helicity-two and helicity-zero bosons.
Arxiv preprint, arXiv:0812.4345, Jan 1, 2008
We consider the production of charged spin-two gauge bosons in the gluon-gluon scattering and cal... more We consider the production of charged spin-two gauge bosons in the gluon-gluon scattering and calculate polarised cross sections for each set of helicity orientations of initial and final particles. The angular dependence of this cross section is compared with the gluon-gluon scattering cross section in QCD.
Thesis Chapters by Spyros Konitopoulos
Η παρούσα μελέτη επιχειρεί να παρουσιάσει τις ιστορικές διακτινώσεις μιας έννοιας που τυγχάνει ευ... more Η παρούσα μελέτη επιχειρεί να παρουσιάσει τις ιστορικές διακτινώσεις μιας έννοιας που τυγχάνει ευρύτατης χρήσης στην καθημερινή πρακτική, διαδραματίζει κεντρικό ρόλο στις σύγχρονες επιστημονικές έρευνες και έχει διανοίξει ένα πεδίο συναρπαστικού διαλόγου στους εσωτερικούς κόλπους της φιλοσοφικής αναζήτησης. Kατά την ανάπτυξη της ιστορικής εκδίπλωσης της έννοιας του χρόνου, θα ακολουθηθεί μια διεπιστημονική προσέγγιση που θα επιχειρήσει να αναδείξει πτυχές αυτού του διαλόγου.
Teaching Documents by Spyros Konitopoulos
Οι σημειώσεις αφορούν μάθημα προχωρημένης Κβαντικής Μηχανικής. Η ανάπτυξη της θεωρίας ακολουθεί μ... more Οι σημειώσεις αφορούν μάθημα προχωρημένης Κβαντικής Μηχανικής. Η ανάπτυξη της θεωρίας ακολουθεί μια ομαδο-θεωρητική κατεύθυνση. Αφού αναλυθούν οι αναπαραστάσεις της ομάδας Poincare, διατυπώνεται η εξίσωση του Dirac και φανερώνονται οι αιτίες που καθιστούν αναγκαία τη δεύτερη κβάντωση. Τα μεθοδολογικά εργαλεία που αναπτύχθηκαν στο πρώτο μισό του μαθήματος, εφαρμόζονται μεθοδικά στην επίλυση προβλημάτων μεταβάσεων και σκέδασης. Τέλος γίνεται μια εισαγωγή στην Κβαντική Θεωρία Πεδίων καθώς και στα Ολοκληρώματα Διαδρομής.
Οι σημειώσεις αυτές αποτελούν μια αυτοτελή μελέτη της Φυσικής των Στοιχειωδών Σωματιδίων και των ... more Οι σημειώσεις αυτές αποτελούν μια αυτοτελή μελέτη της Φυσικής των Στοιχειωδών Σωματιδίων και των Αλληλεπιδράσεων. Οι θεμελιακές αρχές της θεωρίας αναλύονται διεξοδικά και εφαρμόζονται για να κατασκευαστεί το Καθιερωμένο Πρότυπο (Standard Model).
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Papers by Spyros Konitopoulos
Thesis Chapters by Spyros Konitopoulos
Teaching Documents by Spyros Konitopoulos