On initial conditions for the Hot Big Bang

We analyse the process of reheating the Universe in the electroweak theory where the Higgs field plays a role of the inflaton. We estimate the maximal temperature of the Universe and fix the initial conditions for radiation-dominated phase of the Universe expansion in the framework of the Standard Model (SM) and of the nuMSM -- the minimal extension of the SM by three right-handed singlet fermions. We show that the inflationary epoch is followed by a matter dominated stage related to the Higgs field oscillations. We investigate the energy transfer from Higgs-inflaton to the SM particles and show that the radiation dominated phase of the Universe expansion starts at temperature T_r~(3-15)*10^{13} GeV, where the upper bound depends on the Higgs boson mass. We estimate the production rate of singlet fermions at preheating and find that their concentrations at T_r are negligibly small. This suggests that the sterile neutrino Dark Matter (DM) production and baryogenesis in the nuMSM with Higgs-driven inflation are low energy phenomena, having nothing to do with inflation. We study then a modification of the nuMSM, adding to its Lagrangian higher dimensional operators suppressed by the Planck scale. The role of these operators in Higgs-driven inflation is clarified. We find that these operators do not contribute to the production of Warm Dark Matter (WDM) and to baryogenesis. We also demonstrate that the sterile neutrino with mass exceeding 100 keV (a Cold Dark Matter (CDM) candidate) can be created during the reheating stage of the Universe in necessary amounts. We argue that the mass of DM sterile neutrino should not exceed few MeV in order not to overclose the Universe.Comment: 41 pages, 5 figures. Journal version accepted in JCA

Storage Qubits and Their Potential Implementation Through a Semiconductor Double Quantum Dot

In the context of a semiconductor based implementation of a quantum computer the idea of a quantum storage bit is presented and a possible implementation using a double quantum dot structure is considered. A measurement scheme using a stimulated Raman adiabatic passage is discussed.Comment: Revised version accepted for publication in Phys.Rev. B. 19 pages, 4 eps figure

Answering questions and explaining answers : a study of Finnish-speaking children

“The original publication is available at www.springerlink.com”. Copyright Springer. DOI: 10.1007/s10936-007-9067-6 [Full text of this article is not available in the UHRA]This research explores, within the framework of Relevance Theory, how children’s ability to answer questions and explain their answers develops between the ages of 3 and 9 years. Two hundred and ten normally developing Finnish-speaking children participated in this study. The children were asked questions requiring processing of inferential meanings and routines, and were asked to explain their correct answers to elicit understanding about their awareness of how they had derived the answers from the context. The results indicated that the number of correct answers increased rapidly between the ages of 3 years and 4–5 years. Familiarity of context had a significant effect on young children’s ability to answer questions. Becoming aware of the information used in inferencing developed gradually over time between the ages of 3 and 9. Analysis of the children’s incorrect answers and explanations showed that, as children develop, their unsophisticated answer strategies diminish and they increasingly utilize context even in incorrect answers and explanations.Peer reviewe

Complement factor H: using atomic resolution structure to illuminate disease mechanisms.

Complement Factor H has recently come to the fore with variant forms implicated in a range of serious disease states. This review aims to bring together recent data concerning the structure and biological activity of this molecule to highlight the way in which a molecular understanding of function may open novel therapeutic possibilities. In particular we examine the evidence for and against the hypothesis that sequence variations in factor H may predispose to disease if they perturb its ability to recognise and respond appropriately to polyanionic carbohydrates on host surfaces that require protection from complement-mediated damage