Papers by Athanasios Prikas
We study Einstein-Yang-Mills equations in the presence of a gravitating non-topological soliton f... more We study Einstein-Yang-Mills equations in the presence of a gravitating non-topological soliton field configuration consisted of a Higgs doublet, in Brans-Dicke and general scalar-tensor gravitational theories. The results of General Relativity are reproduced in the ω BD , ω 0 → ∞ limit. The numerical solutions correspond to a soliton star with a non-abelian gauge field. We study the effects of the coupling constant, the frequency of the Higgs field and the Brans-Dicke field on the soliton parameters.
We study Einstein-Yang-Mills equations in the presence of gravitating non-topological soliton fie... more We study Einstein-Yang-Mills equations in the presence of gravitating non-topological soliton field configurations, of q-ball type. We produce numerical solutions, stable with respect to gravitational collapse and to fission into free particles, and we study the effect of the field strength and the eigen-frequency to the soliton parameters. We also investigate the formation of such soliton stars when the spacetime is asymptotically anti de Sitter. PACS number(s): 04.70.Bw, 04.20.Jb e-mail: [email protected]
The purposes of the present article are: a) To show that non-locality leads to the transfer of ce... more The purposes of the present article are: a) To show that non-locality leads to the transfer of certain amounts of energy and angular momentum at very long distances, in an absolutely strange and unnatural manner, in any model reproducing the quantum mechanical results. b) To prove that non-locality is the result only of the zero spin state assumption for distant particles, which explains its presence in any quantum mechanical model. c) To reintroduce locality, simply by denying the existence of the zero spin state in nature (the so-called highly correlated, or EPR singlet state) for particles non-interacting with any known field. d) To propose a realizable experiment to clarify if two remote (and thus non-interacting with a known field) particles, supposed to be correlated as in Bell-type experiments, are actually in zero spin state.
Physics Letters B, 2005
We study q-stars in Brans-Dicke gravitational theory. We find that when the Brans-Dicke constant,... more We study q-stars in Brans-Dicke gravitational theory. We find that when the Brans-Dicke constant, ω BD , tends to infinity, the results of General Relativity are reproduced. For other values of ω BD , the particle number, mass and radius of the star and the absolute value of the matter field are a few percent larger than in the case of General Relativity. We also investigate the general scalar-tensor gravitational theory and find that the star parameters are a few percent larger than in the case of General Relativity.
Physical Review D, 2004
We study q-stars with global and local U (1) symmetry in extra dimensions in asymptotically anti ... more We study q-stars with global and local U (1) symmetry in extra dimensions in asymptotically anti de Sitter or flat spacetime. The behavior of the mass, radius and particle number of the star is quite different in 3 dimensions, but in 5, 6, 8 and 11 dimensions is similar to the behavior in 4.
Physical Review D, 2005
We study Einstein-Yang-Mills equations in the presence of a gravitating non-topological soliton f... more We study Einstein-Yang-Mills equations in the presence of a gravitating non-topological soliton field configuration consisted of a Higgs doublet, in Brans-Dicke and general scalar-tensor gravitational theories. The results of General Relativity are reproduced in the ω BD , ω 0 → ∞ limit. The numerical solutions correspond to a soliton star with a non-abelian gauge field. We study the effects of the coupling constant, the frequency of the Higgs field and the Brans-Dicke field on the soliton parameters.
Physical Review D, 2002
We present the formalism of q-stars with local or global U (1) symmetry. The equations we formula... more We present the formalism of q-stars with local or global U (1) symmetry. The equations we formulate are solved numerically and provide the main features of the soliton star. We study its behavior when the symmetry is local in contrast to the global case. A general result is that the soliton remains stable and does not decay into free particles and the electrostatic repulsion preserves it from gravitational collapse. We also investigate the case of a q-star with non-minimal energy-momentum tensor and find that the soliton is stable even in some cases of collapse when the coupling to gravity is absent.
Nuclear Physics B, 2004
We study q-stars with one or two scalar fields, non-abelian, and fermion-scalar q-stars in 2 + 1 ... more We study q-stars with one or two scalar fields, non-abelian, and fermion-scalar q-stars in 2 + 1 dimensions in an anti de Sitter or flat spacetime. We fully investigate their properties, such as mass, particle number, radius, numerically, and focus on the matter of their stability against decay to free particles and gravitational collapse. We also provide analytical solutions in the case of flat spacetime and other special cases.
New Journal of Physics, 2003
We investigate the phase space of parameters in the Pati-Salam model derived in the context of D-... more We investigate the phase space of parameters in the Pati-Salam model derived in the context of D-branes scenarios, requiring low energy string scale. We find that a non-supersymmetric version complies with a string scale as low as ∼ 10 TeV, while in the supersymmetric version the string scale raises up to ∼ 2 × 10 7 TeV. The limited energy region for RGE running demands a large tan β in order to have experimentally acceptable masses for the top and bottom quarks.
Journal of Mathematical Physics, 2006
We study domain-wall networks on the surface of q-stars in asymptotically flat or anti de Sitter ... more We study domain-wall networks on the surface of q-stars in asymptotically flat or anti de Sitter spacetime. We provide numerical solutions for the whole phase space of the stable field configurations and find that the mass, radius and particle number of the star is larger but the scalar field, responsible for the formation of the soliton, acquires smaller values when a domain-wall network is entrapped on the star surface.
Journal of Mathematical Physics, 2006
We present Jordan-Brans-Dicke and general scalar-tensor gravitational theory in extra dimensions ... more We present Jordan-Brans-Dicke and general scalar-tensor gravitational theory in extra dimensions in an asymptotically flat or anti de Sitter spacetime. We consider a special gravitating, boson field configuration, a q-star, in 3, 4, 5 and 6 dimensions, within the framework of the above gravitational theory and find that the parameters of the stable stars are a few per cent different from the case of General Relativity.
In various supersymmetric extensions of the Standard Model there appear non-topological solitons ... more In various supersymmetric extensions of the Standard Model there appear non-topological solitons due to the existence of U(1) global symmetries associated with Baryon and/or Lepton quantum numbers. Trilinear couplings (A-terms) in the scalar potential break explicitly the U(1) invariance. We investigate numerically the stability of these objects in the case that this breaking is small. We find that stable configurations, oscillating though, can still appear. Other relevant properties are also examined.
General Relativity and Gravitation, 2004
We study q-stars with various symmetries in anti de Sitter spacetime in 3 + 1 dimensions. Compari... more We study q-stars with various symmetries in anti de Sitter spacetime in 3 + 1 dimensions. Comparing with the case of flat spacetime, we find that the value of the field at the center of the soliton is larger when the other parameters show a more complicated behavior. We also investigate their phase space when the symmetry is local and the effect of the charge to its stability.
International Journal of Modern Physics A, 2005
In the present work we investigate the existence and stability properties of q-balls which consis... more In the present work we investigate the existence and stability properties of q-balls which consist of a couple of scalar fields, forming an SU (2) doublet in a Lagrangian with a global SU (2) symmetry. We find that these spinors can form a localized and stable field configuration, if they rotate in their internal SU (2) space. We find the energy and charge of the soliton in both thin and thick-wall approximation and we prove its stability against decaying to free particles. We also find the asymptotic forms of the scalar and gauge field and the energy and charge of the configuration when the SU (2) symmetry is local. The only assumption is the smallness of the coupling constant g. Using numerical methods we prove the stability of the q-ball in the local case.
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Papers by Athanasios Prikas