1,432 research outputs found
Hitchin Fibrations on Two-Dimensional Moduli Spaces of Irregular Higgs Bundles with One Singular Fiber
We analyze and completely describe the four cases when the Hitchin fibration
on a -dimensional moduli space of irregular Higgs bundles over
has a single singular fiber. The case when the fiber at
infinity is of type is further analyzed, and we give constructions of
all the possible configurations of singular curves inelliptic fibrations having
this type of singular fiber at infinity
The twistor geometry of three-qubit entanglement
A geometrical description of three qubit entanglement is given. A part of the
transformations corresponding to stochastic local operations and classical
communication on the qubits is regarded as a gauge degree of freedom. Entangled
states can be represented by the points of the Klein quadric a space
known from twistor theory. It is shown that three-qubit invariants are
vanishing on special subspaces of . An invariant vanishing for the
class is proposed. A geometric interpretation of the canonical
decomposition and the inequality for distributed entanglement is also given.Comment: 4 pages RevTeX
Optimális éves viselkedési modellek: út a fiziológiától a populációkig? = Optimal annual routines: a path from physiology to populations?
A pályázat fő célja annak kiderítése volt, hogy a különböző állapotváltozók hogyan befolyásolják az optimális viselkedést, speciálisan a hogyan befolyásolják a fő életmenet események időzítését az éves cikluson belül. E cél elérése érdekében több modellt fejlesztettünk, és változatos terepi megfigyeléseket és aviáriumi kísérleteket folytattunk. Fő modelljeink azt mutatják, hogy az állapotváltozók (pl. tollminőség, energiatartalékok) jelentősen befolyásolhatják a vedlés és vándorlás időzítését, de a táplálékforrás időbeli eloszlása és szezonalitása is jelentős hatással lehet. Fő empirikus eredményeink szerint a táplálék minősége és a paraziták fertőzése jelentősen befolyásolhatja a tollminőséget. Egy komparatív vizsgálatban kimutattuk, hogy a vándorlás időzítését a különféle életmenet jellemzők jelentősen befolyásolják, de a szexuálisan szelektált jellegeknek nincs ilyen hatása. | The main aim of the project was to investigate how state variables effect optimal behaviour in general, and the optimal timing of major life history events over the annual cycle, in particular. To accomplish this aim we developed a couple of annual routine models and performed various field observations and aviary experiments. Our main models show that state variables (quality of feathers, energy reserves) can significantly influence the timing of optimal behaviour (moult, migration) but they also underline the importance of the temporal distribution and seasonality of food sources. Our main empirical results show that diet quality and parasite infection influence feather quality considerably. By a comparative study we found that life history traits (e.g. migration distance and diet) but not sexually selected traits influence the timing of migration
Microstructure formation in electrodeposited Co-Cu/Cu multilayers with GMR effect: influence of current density during the magnetic layer deposition
The influence of the current density applied during the deposition of the magnetic layers on the microstructure formation in electrodeposited Co-Cu/Cu multilayers and on their giant magnetoresistance (GMR) was investigated using a combination of magnetoresistance measurements, wide-angle and small-angle X-ray scattering, high-resolution transmission electron microscopy, atomic force microscopy and chemical analysis. The magnetoresistance measurements revealed that a reduction of the current density stimulates a transition from the formation of the magnetic layers with predominantly ferromagnetic character to the formation of superparamagnetic regions. As based on electrochemical considerations, it was supposed that such a change in the magnetic properties can be caused by an increased amount of Cu codeposited with Co at low current densities. It turned out from the structural studies that a pronounced segregation of Co and Cu occurs at low current densities. In accordance with their very low mutual solubility at room temperature, no atomic scale intermixing of Co and Cu could be detected. The segregation of Cu and Co was related to the fragmentation of the magnetic layers, to the enhancement of the local lattice strains, to the increase of the interface corrugations, to the partial loss of the multilayer periodicity and finally to the formation of Co precipitates in the Cu matrix
Quarkonia Correlators Above Deconfinement
We study the quarkonia correlators above deconfinement using the potential
model with screened temperature-dependent potentials. We find that while the
qualitative features of the spectral functions, such as the survival of the 1S
state, can be reproduced by potential models, the temperature dependence of the
correlators disagree with the recent lattice data.Comment: 21 pages, 26 eps figure
Optimális vedlési stratégiák = Optimal moult strategies
A pályázat fő célja annak kiderítése volt, hogy a különböző állapotváltozók hogyan befolyásolják az optimális viselkedést, speciálisan a hogyan befolyásolják a fő életmenet események időzítését az éves cikluson belül. E cél elérése érdekében több modellt fejlesztettünk, és változatos terepi megfigyeléseket és aviáriumi kísérleteket folytattunk. Fő modelljeink azt mutatják, hogy az állapotváltozók (pl. tollminőség, energiatartalékok) jelentősen befolyásolhatják a vedlés és vándorlás időzítését, de a táplálékforrás időbeli eloszlása és szezonalitása is jelentős hatással lehet. Fő empirikus eredményeink szerint a táplálék minősége és a paraziták fertőzése jelentősen befolyásolhatja a tollminőséget. Egy komparatív vizsgálatban kimutattuk, hogy a vándorlás időzítését a különféle életmenet jellemzők jelentősen befolyásolják, de a szezuálisan szelektált jellegeknek nincs ilyen hatása. | The main aim of the project was to investigate how state variables effect optimal behaviour in general, and the optimal timing of major life history events over the annual cycle, in particular. To accomplish this aim we developed a couple of annual routine models and performed various field observations and aviary experiments. Our main models show that state variables (quality of feathers, energy reserves) can significantly influence the timing of optimal behaviour (moult, migration) but they also underline the importance of the temporal distribution and seasonality of food sources. Our main empirical results show that diet quality and parasite infection influence feather quality considerably. By a comparative study we found that life history traits (e.g. migration distance and diet) but not sexually selected traits influence the timing of migration
Small amplitude quasi-breathers and oscillons
Quasi-breathers (QB) are time-periodic solutions with weak spatial
localization introduced in G. Fodor et al. in Phys. Rev. D. 74, 124003 (2006).
QB's provide a simple description of oscillons (very long-living spatially
localized time dependent solutions). The small amplitude limit of QB's is
worked out in a large class of scalar theories with a general self-interaction
potential, in spatial dimensions. It is shown that the problem of small
amplitude QB's is reduced to a universal elliptic partial differential
equation. It is also found that there is the critical dimension, ,
above which no small amplitude QB's exist. The QB's obtained this way are shown
to provide very good initial data for oscillons. Thus these QB's provide the
solution of the complicated, nonlinear time dependent problem of small
amplitude oscillons in scalar theories.Comment: 24 pages, 19 figure
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