Yiannis Contoyiannis
University of the West
Particle physicsMagnetic fieldQuantum chromodynamicsPhysicsStatistical physicsCriticalitySpontaneous symmetry breakingGeologyCritical point (thermodynamics)Phase transitionCritical exponentSeismologyField (physics)Critical phenomenaSymmetry breakingCondensed matter physicsIntermittencyMathematicsFracture (geology)Ising modelRenormalization groupGeophysicsPower law
68Publications
19H-index
706Citations
Publications 64
Newest
The problem of the phase transition of a Z(3) spin system is a complex issue. A numerical simulation in the framework of the mean field theory using the Metropolis algorithm reveals: (a) the existence of second order phase transition with a degenerated critical point which could be considered as a state of resonance (b) hysteresis phenomena which are accompanied with tricritical crossover around the end point of first order transition. Based on these results we propose a scenario about confineme...
Based on the saddle point approximation in G-L theory of the critical phenomena we construct two-dimensional Poincare maps which describe the symmetry breaking (SB) and the tricritical crossover phenomenon in Physics. The phase space diagrams of these maps are in agreement with the theoretical predictions. A correction in these maps close to the critical point for small values of the order parameter is attempted. Finally we demonstrate that numerical experiments verify the correctness of these m...
#2A. SchekotovH-Index: 14
Last. C. Nomicos (UWest: University of the West)H-Index: 5
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This paper reports an attempt to use ultra-low-frequency (ULF) magnetic field data from a space weather monitoring magnetometer array in the study of earthquake (EQ) precursors in Greece. The data from four magnetometer stations of the HellENIc GeoMagnetic Array (ENIGMA) have been analyzed in the search for possible precursors to a strong EQ that occurred south of Lesvos Island on 12 June 2017, with magnitude Mw = 6.3 and focal depth = 12 km. The analysis includes conventional statistical method...
9 CitationsSource
#1Stelios M. Potirakis (UWest: University of the West)H-Index: 17
#2Yiannis Contoyiannis (UWest: University of the West)H-Index: 19
Last. Masashi Hayakawa (University of Electro-Communications)H-Index: 69
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Abstract The method of critical fluctuations (MCF) is a time series analysis method which provides a way of both identifying the critical state and the departure from it. Its application to the ground-based ultra-low frequency (ULF) magnetic field fluctuations observed prior to the very strong earthquakes (EQs) of magnitudes M W = 6 . 2 , M W = 6 . 0 and M W = 7 . 0 which sequentially took place within a two days period (April 14–15, 2016) in Southwest Japan under the city of Kumamoto reveals wh...
7 CitationsSource
Last. Constantinos NomicosH-Index: 21
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In this letter we present preliminary results concerning precursors to the recent significant (Mw 6.7) earthquake (EQ) that took place in the region south of the Greek Island of Zakynthos (October 25, 2018). We show, in terms of fracture-induced electromagnetic emissions (EME), that the Earth system around the focal area was at critical state up to a few hours before the occurrence of the EQ. Importantly, departure from the critical state, in terms of the symmetry breaking phenomenon, was also i...
#1Efstratios K. Kosmidis (A.U.Th.: Aristotle University of Thessaloniki)H-Index: 15
#2Yiannis Contoyiannis (UWest: University of the West)H-Index: 19
Last. Fotios K. Diakonos (UoA: National and Kapodistrian University of Athens)H-Index: 13
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: Evidence that neural circuits are operating near criticality has been provided at various levels of brain organisation with a presumed role in maximising information processing and multiscale activity association. Criticality has been linked to excitation at both the single-cell and network levels, as action potential generation marks an obvious phase transition from a resting to an excitable state. Using in vitro intracellular recordings, we examine irregular, small amplitude membrane potenti...
4 CitationsSource
8 CitationsSource
#1Georgios BalasisH-Index: 21
#2Ioannis A. Daglis (UoA: National and Kapodistrian University of Athens)H-Index: 37
Last. Charalampos KontoesH-Index: 2
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9 CitationsSource
#1Konstantinos Eftaxias (UoA: National and Kapodistrian University of Athens)H-Index: 29
#2Stelios M. Potirakis (UWest: University of the West)H-Index: 17
Last. Yiannis Contoyiannis (UWest: University of the West)H-Index: 4
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Abstract Based on a multidisciplinary analysis, the following four-stage model of earthquake (EQ) dynamics by means of precursory electromagnetic (EM) emissions (EMEs) has been proposed. The initially observed MHz EM anomaly is due to the fracture of the highly heterogeneous system that surrounds the formation of strong brittle and high-strength entities (asperities) distributed along the rough surfaces of the main fault sustaining the system. The MHz EME can be described by means of a second-or...
8 CitationsSource