Mass generation and the dynamical role of the Katoptron Group

Heavy mirror fermions along with a new strong gauge interaction capable of breaking the electroweak gauge symmetry dynamically were recently introduced under the name of katoptrons. Their main function is to provide a viable alternative to the Standard-Model Higgs sector. In such a framework, ordinary fermions acquire masses after the breaking of the strong katoptron group which allows mixing with their katoptron partners. The purpose of this paper is to study the elementary-scalars-free mechanism responsible for this breaking and its implications for the fermion mass hierarchies.Comment: 15 LaTeX pages, some comments added, version published in Modern Physics Letters

Uncertainty in Crowd Data Sourcing under Structural Constraints

Applications extracting data from crowdsourcing platforms must deal with the uncertainty of crowd answers in two different ways: first, by deriving estimates of the correct value from the answers; second, by choosing crowd questions whose answers are expected to minimize this uncertainty relative to the overall data collection goal. Such problems are already challenging when we assume that questions are unrelated and answers are independent, but they are even more complicated when we assume that the unknown values follow hard structural constraints (such as monotonicity). In this vision paper, we examine how to formally address this issue with an approach inspired by [Amsterdamer et al., 2013]. We describe a generalized setting where we model constraints as linear inequalities, and use them to guide the choice of crowd questions and the processing of answers. We present the main challenges arising in this setting, and propose directions to solve them.Comment: 8 pages, vision paper. To appear at UnCrowd 201

TECTONO-SEDIMENTARY EVOLUTION AND RATES OF TECTONIC UPLIFT OF THE SFAKIA COASTAL ZONE, SOUTHWESTERN CRETE

Η περιοχή των Σφακιών είναι μία στενή παράκτια ζώνη στο νοτιοδυτικό τμήμα των Λευκών Ορέων, στο οποίο διασώζεται τμήμα του Νότιου Κρητικού περιθωρίου. Πρόκειται για μία μακρόχρονη νεοτεκτονική δομή που άρχισε τη δράση της στο Ανώτερο Μειόκαινο και συνεχίζεται μέχρι σήμερα. Χαρακτηρίζεται από μία απότομη μορφολογική ασυνέχεια διεύθυνσης Α-Δ, που σχηματίστηκε από ρήγματα διεύθυνσης Α-Δ και ΑΝΑ-ΔΒΔ προκαλώντας εφελκυσμό Β-Ν. Από το Ανώτερο Μειόκαινο μέχρι το Κατώτερο Π?.ειστόκαινο αποτέθηκαν θαλάσσια, ενώ ακολούθως η ιζηματογένεση συνεχίστηκε με την απόθεση μεγά).ου πάχους αλλουβιακών ριπιδιών, διαδικασία που συνεχίζεται μέχρι σήμερα. Η καλύτερη στοιχειοθέτηση της ηλικίας των θαλάσσιων ιζημάτων σε συνδυασμό με πρόσφατα δημοσιεύματα σχετικά με το βάθος απόθεσης τους και με τη χαρτογράφηση των ρηγμάτων της περιοχής, έδωσε τη δυνατότητα να προβούμε σε σημαντικές διαπιστώσεις σχετικά με τους μακροχρόνιους ρυθμούς ανύψωσης των ρηξιτεμαχών της περιοχής, όπως και για το χρονικό διάστημα που τα ρήγματα που ορί- ζουν αυτά τα ρηξιτεμάχη ήταν ενεργά. Από το Μέσο Πλειόκαινο όλη η περιοχή υπόκειται σε ανύψωση με τις εσωτερικές περιοχές να έχουν ρυθμούς έως και διπλάσιους από εκείνους της παράκτιας ζώνης. Η γενική ανύψωση φαίνεται να ελέγχεται από ρήγματα υποθαλάσσια νότια της περιοχής μελέτης.Sfakia lies within a narrow coastal zone at the southwestern foothills of the Lefka Ori Mt. Here a segment of the South Cretan margin is preserved onshore, a structure that represents a neotectonic structure with continuous activity since the Upper Miocene. This segment is characterized by a steep, E-W striking and south facing morphological escarpment that constitutes numerous E-W and ESE-WNW striking normal faults. Since the Late Miocene, marine sequences of Tortonian, Early Pliocene and Lower Pleistocene age were deposited along the coastal zone. Since the Middle Pleistocene multiple, coalescent alluvial fans covered both the alpine basement and the marine sediments. Fault-kinematic- and stratigraphie data combined with recently published palaeobathymetry reconstructions allow us to make relable estimates of both the uplift rates of fault blocks in the study area and the period that the faults that demarcate them were active. The results show that the study area is experiencing uplift already since the Middle Pliocene and that the uplift rates of the mountainous parts are higher than those of the coastal zone. The general uplift of the coastal zone seems to be controlled by offshore normal faults, south of Sfaki

Paleobathymetry of a pliocene voutes coast (Heraklion, Crete)

The fish otolith assemblages identified in the Zanclean sediments of Voutes section (Heraklion, Crete) are analyzed in order to estimate the depth of deposition. The assemblages indicate that Voutes area was in fact a coast inhabited by a neritic fish fauna with significant mesopelagic component, mostly Myctophids. The benthic and benthopelagic group exhibits great diversity. In the late Zanclean, the study area corresponds to a deep neritic environment, which gradually uplifts. At the end of the Zanclean, Voutes area becomes a very shallow coast, as shown by the increased contribution to the assemblage by members of the Gobiid family, as well as the notable presence of Bothidae. Thereafter, the area deepens again, as the shallow benthic-benthopelagic component significantly decreases. This is consistent with the appearance of Pteropods and reaches a peak during the deposition of diatomites at maximum depth. At the upper part of the section, the sea bottom depth decreases again to allow for the deposition of marls with various molluscs remains, where Gadids and Gobiids again reappear. Finally, the upper diatomitic horizon is characterized by a rather poor fish fauna. These observations allow reconstructing the evolution of Voutes coastal area during the latest Zanclean until the Piacenzian. Στην παρούσα εργασία παρουσιάζεται η παλαιοβαθυμετρική ανάλυση των συναθροίσεων ωτολίθων Ιχθύων, που προσδιορίστηκαν στα ιζήματα ηλικίας Ζαγκλίου στην τομή Βούτες (Ηράκλειο, Κρήτη). Η περιοχή Βούτες αποτελούσε μία ακτή με νηριτική Ιχθυοπανίδα, με υψηλή συμμετοχή μεσοπελαγικών ειδών, κυρίων Myctophidae. Τα βενθικά και βενθοπελαγικά ψάρια εμφανίζουν επίσης μεγάλη ποικιλότητα. Κατά το ανώτερο Ζάγκλιο, η περιοχή μελέτης αντιστοιχούσε σε βαθύ νηριτικό περιβάλλον. Σταδιακά η περιοχή ανυψώθηκε σε πολύ μικρά βάθη, όπως φαίνεται από την αυξημένη συμμετοχή στην πανίδα των Gobidae, αλλά και την παρουσία Bothidae. Στη συνέχεια, η περιοχή βάθυνε ξανά, καθώς παρατηρείται σημαντική μείωση της συμμετοχής των ρηχών βενθικών-βενθοπελαγικών ειδών. Το συμπέρασμα αυτό ενισχύεται από την παρουσία στο επίπεδο αυτό των Πτεροπόδων, αλλά και την απόθεση διατομιτών. Σε ανώτερο τμήμα της τομής, το βάθος της θάλασσας μειώνεται και πάλι, πριν τον ανώτερο διατομιτικό ορίζοντα, ο οποίος ωστόσο εμφανίζει ιδιαίτερα φτωχή συνάθροιση ωτολίθων

Longitudinal and transverse fermion-boson vertex in QED at finite temperature in the HTL approximation

We evaluate the fermion-photon vertex in QED at the one loop level in Hard Thermal Loop approximation and write it in covariant form. The complete vertex can be expanded in terms of 32 basis vectors. As is well known, the fermion-photon vertex and the fermion propagator are related through a Ward-Takahashi Identity (WTI). This relation splits the vertex into two parts: longitudinal (Gamma_L) and transverse (Gamma_T). Gamma_L is fixed by the WTI. The description of the longitudinal part consumes 8 of the basis vectors. The remaining piece Gamma_T is then written in terms of 24 spin amplitudes. Extending the work of Ball and Chiu and Kizilersu et. al., we propose a set of basis vectors T^mu_i(P_1,P_2) at finite temperature such that each of these is transverse to the photon four-momentum and also satisfies T^mu_i(P,P)=0, in accordance with the Ward Identity, with their corresponding coefficients being free of kinematic singularities. This basis reduces to the form proposed by Kizilersu et. al. at zero temperature. We also evaluate explicitly the coefficient of each of these vectors at the above-mentioned level of approximation.Comment: 13 pages, uses RevTe

Evidence for a possible life-cycle association between Syracosphaera protrudens (heterococcolithophore) and Syracosphaera pulchra HOL pirus -type (holococcolithophore)

Abstract. An apparently unambiguous combination coccosphere from the Eastern Mediterranean (Aegean Sea, Greece) is documented involving Syracosphaera protrudens Okada & McIntyre, 1977 and Syracosphaera pulchra Lohmann, 1902 HOL pirus-type. This finding is difficult to interpret in terms of the current understanding of Syracosphaera taxonomy and adds evidence to the hypothesis of a distinctly complex Syracosphaera pulchra life cycle

New physics with mirror particles

The introduction of mirror fermions with masses between the weak scale and 1 TeV could offer a dynamical origin to the standard-model electro-weak symmetry breaking mechanism. The purpose of this work is to study the dynamics needed in order to render models with such a fermion content phenomenologically acceptable.Comment: 28 LaTeX pages, to appear in the Journal of Physics