42 research outputs found
Particle physics model of curvaton inflation in a stable universe
We investigate a particle physics model for cosmic inflation based on the
following assumptions: (i) there are at least two complex scalar fields; (ii)
the scalar potential is bounded from below and remains perturbative up to the
Planck scale; (iii) we assume slow-roll inflation with maximally correlated
adiabatic and entropy fluctuations 50--60 e-folds before the end of inflation.
The energy scale of the inflation is set automatically by the model. Assuming
also at least one massive right handed neutrino, we explore the allowed
parameter space of the scalar potential as a function of the Yukawa coupling of
this neutrino
Calculation of the decay rate of tachyonic neutrinos against charged-lepton-pair and neutrino-pair Cerenkov radiation
We consider in detail the calculation of the decay rate of high-energy
superluminal neutrinos against (charged) lepton pair Cerenkov radiation (LPCR),
and neutrino pair Cerenkov radiation (NPCR), i.e., against the decay channels
nu -> nu e+ e- and nu -> nu nubar nu. Under the hypothesis of a tachyonic
nature of neutrinos, these decay channels put constraints on the lifetime of
high-energy neutrinos for terrestrial experiments as well as on cosmic scales.
For the oncoming neutrino, we use the Lorentz-covariant tachyonic relation E_nu
= (p^2 - m_nu^2)^(1/2), where m_nu is the tachyonic mass parameter. We derive
both threshold conditions as well as decay and energy loss rates, using the
plane-wave fundamental bispinor solutions of the tachyonic Dirac equation.
Various intricacies of rest frame versus lab frame calculations are
highlighted. The results are compared to the observations of high-energy
IceCube neutrinos of cosmological origin.Comment: 29 pages; RevTe
Járműdinamikai rendszerek integrált fuzzy-sztochasztikus modellezése és identifikációja = Integrated Modeling and Identification of Vehicle Dynamic Systems
A kutatĂłmunka a lineáris Ă©s a nemlineáris járműdinamikai rendszerek a bizonytalansági tĂ©nyezĹ‘ket is figyelembe vevĹ‘ Ăşj tĂpusĂş modellezĂ©si eljárásainak Ă©s rendszeridentifikáciĂłs algoritmusainak kidolgozásával foglalkozik. A járműdinamikai modellezĂ©s metodolĂłgiai megközelĂtĂ©se a hagyományos statisztikai rendszeridentifikáciĂłs mĂłdszerek mellett alkalmazza a kĂĽlönbözĹ‘ lágy számĂtástudományi megközelĂtĂ©si mĂłdokat, Ăgy többek között felhasználja a fuzzy logika, fuzzy irányĂtástechnika algoritmusait, a neurális Ă©s fuzzy-neurális hálĂłzatokat, továbbá a szinguláris Ă©rtĂ©kdekompozĂciĂł (SVD) mĂłdszereit, kapcsolatot teremtve az LPV rendszereken Ă©rtelmezett Takagi-Sugeno tĂpusĂş fuzzy irányĂtási algoritmusok Ă©s a magasabb rendű szinguláris Ă©rtĂ©k dekompozĂciĂł között. A nemlineáris járműdinamikai rendszerek komplex modellezĂ©sĂ©nĂ©l foglalkozunk a hatĂ©kony komplexitás csökkentĹ‘ technikák kidolgozásával is, fuzzy interpoláciĂłs eljárások alkalmazásával, ahol a tömeges adatfeldolgozást multiprocesszoros számĂtások segĂtsĂ©gĂ©vel vĂ©gezzĂĽk el. A lineáris járműdinamikai modellezĂ©s során összehasonlĂtjuk a szabályalapĂş fuzzy irányĂtástechnikai eljárásokkal kapott eredmĂ©nyeket a sztochasztikus identifikáciĂłs mĂłdszerek becslĂ©sĂ©vel, a transzferfĂĽggvĂ©nyek illetve a transzfermátrixok kĂĽlönbözĹ‘ tĂpusĂş approximáciĂłja alapján. | This research project deals with the construction and development of new models of "uncertain principles" for the description of linear and nonlinear vehicle system dynamics using efficient new stochastic, fuzzy modelling approaches and identification algorythms. The methodological approach of the vehicle dynamics modelling is not only based on the traditional statistical system idetificaion methods, but on those soft computing approaches using among others fuzzy logic and fuzzy control algorythms, neural and fuzzy-neural networks, new singular value decomposition methods, establishing interconnection between Takagi-Sugeno type control models interpreted for LPV systems and higher order singular value decomposition (HOSVD). In the large-scale and complex modelling of the nonlinear vehicle system dynamics efficient complexity reduction techniques and fuzzy interpolative methods will be applied for the realization of the mass-data processing on the basis of multiprocessor computational intelligence. In the linear vehicle dynamic modelling a comparison will be examined between the rulebased fuzzy control approaches and modelling of the well-known modern stochastic identification methods on the basis of different transfer function and transfer matrix approximations