Curvature estimates for stable marginally trapped surfaces

We derive integral and sup-estimates for the curvature of stably marginally outer trapped surfaces in a sliced space-time. The estimates bound the shear of a marginally outer trapped surface in terms of the intrinsic and extrinsic curvature of a slice containing the surface. These estimates are well adapted to situations of physical insterest, such as dynamical horizons.Comment: 28 pages. This is a major rework of the previous version. It extends the curvature estimates to no longer require global area bounds. In addition some mistakes were correcte

Stability estimates with a priori bound for the inverse local Radon transform

We consider the inverse problem for the $2$-dimensional weighted local Radon transform $R_m[f]$, where $f$ is supported in $y\geq x^2$ and $R_m[f](\xi,\eta)=\int f(x, \xi x + \eta) m(\xi, \eta, x)\,\text{d} x$ is defined near $(\xi,\eta)=(0,0)$. For weight functions satisfying a certain differential equation we give weak estimates of $f$ in terms of $R_m[f]$ for functions $f$ that satisfies an a priori bound.Comment: 34 page

Some aspects of random utility, extreme value theory and multinomial logit models

In this paper we give a survey on some basic ideas related to random utility, extreme value theory and multinomial logit models. These ideas are well known within the field of spatial economics, but do not appear to be common knowledge to researchers in probability theory. The purpose of the paper is to try to bridge this gap.Random utility theory; extreme value theory; multinomial logit models; entropy.

Forecasting the fast and frugal way: A study of performance and information-processing strategies of experts and non-experts when predicting the World Cup 2002 in soccer

This paper investigates forecasting performance and judgmental processes of experts and non-experts in soccer. Two circumstances motivated the paper: (i) little is known about how accurately experts predict sports events, and (ii) recent research on human judgment suggests that ignorance-based decision-strategies may be reliable. About 250 participants with different levels of knowledge of soccer took part in a survey and predicted the outcome of the first round of World Cup 2002. It was found that the participating experts (i.e., sport journalists, soccer fans, and soccer coaches) were not more accurate than the non-experts. Experts overestimated their performance and were overconfident. While the experts claimed to have relied on analytical approaches and much information, participants with limited knowledge stated that their forecasts were based upon recognition and few pieces of information. The paper concludes that a recognition-based strategy seems to be appropriate when forecasting worldwide soccer events.Expert predictions; Information use; Judgmental forecasting; Overconfidence; Recognition heuristic; Sports forecasting

Analysis of roles and position of mobile network operators in mobile payment infrastructure

A number of different mobile payment solutions have been presented the last decade. The phone subscription with its security mechanisms are used for user identification and payments. This is the case for SMS based payment and ticketing systems that are getting more and more popular. However, there are other ways to implement a Trusted Element (TE) , where a SIM card architecture is only one. It can be in the mobile phone, as a separate integrated circuit, as an optional customer deployed plug-in device (e.g., microSD) or be running as an application on a server existing entirely as software. In this paper we analyze what roles and responsibilities different actors have in different types of mobile payments solutions. The main focus is on the implications for the mobile operator business. It turns out that new types of intermediary actors in most cases play an important role. Sometimes mobile operators are not even involved. The emergence of new payment together with other non-SIM card based TE solutions opens up for many different market scenarios for mobile payment services. --

Can mobile eco-systems for technical innovations be standardized? The case of mobile wallets and contactless communication

This paper puts focus on the application of Near Field Communication technology (NFC) to mobile payments. Uncertainties about global policies open for a variety of local business policies. Taking into account different representations of actor interaction as described by different eco-systems by different policy forums the main research question to be discussed in the paper is: Can policies or standards describing actor roles and responsibilities for technical innovations like mobile payments remove obstacles for introduction of the innovation? Different types of industry forums are not only involved in strictly technical matters but also discuss and describe visions about how a new technique might be applied in business life. They suggest different business architectures, (not only a technical architecture), where roles of different type of actors and relations between actors are outlined based on ideas about so called eco-systems. Against this background the paper first discusses how NFC enabled mobile payments currently attracts a lot of attention and identifies four possible development paths making it happen. The paper discusses and compares how global policy networks describe the technical and business architectures for mobile payments. The paper uses a business practice analytical framework and an industrial network framework to identify major problems in connecting global and local policies. Some comments on further research finalize the paper. --Near Field Communication,mobile payments,global policy,business architecture,policy forum,industrial networks,practice

The time evolution of marginally trapped surfaces

In previous work we have shown the existence of a dynamical horizon or marginally trapped tube (MOTT) containing a given strictly stable marginally outer trapped surface (MOTS). In this paper we show some results on the global behavior of MOTTs assuming the null energy condition. In particular we show that MOTSs persist in the sense that every Cauchy surface in the future of a given Cauchy surface containing a MOTS also must contain a MOTS. We describe a situation where the evolving outermost MOTS must jump during the coalescence of two seperate MOTSs. We furthermore characterize the behavior of MOTSs in the case that the principal eigenvalue vanishes under a genericity assumption. This leads to a regularity result for the tube of outermost MOTSs under the genericity assumption. This tube is then smooth up to finitely many jump times. Finally we discuss the relation of MOTSs to singularities of a space-time.Comment: 21 pages. This revision corrects some typos and contains more detailed proofs than the original versio

Sweden has effectively used bilateral co-operation with the US and other European states as an alternative to NATO membership.

Sweden is one of only a handful of EU countries which are not members of NATO. Jan Joel Andersson provides an overview of Swedish defence policy and assesses the potential for Sweden to use the EU as an alternative to NATO membership. He argues that the myth of the country’s policy of ‘armed neutrality’ during the Cold War is still a key obstacle to gaining public support for joining NATO. However in practice Sweden has effectively used informal bilateral co-operation with the US and other European states to ensure its security

Social differentials in speed-premium effects in childbearing in Sweden

In Sweden, parents receive a parental-leave allowance of a high percentage of their pre-birth salary for about a year in connection with any birth. (The percentage has changed over time, as has the period for which it is paid. For a birth that appears in 2005, parents get 80% of the salary for thirteen months.) If they space their births sufficiently closely, they avoid a reduction in the allowance caused by any reduced income earned between the births. The gain is popularly called a “speed premium”. After some precursors in legal practice, this rule was made statutory in 1980 and the “eligibility interval” was then set to 24 months. In 1986, it was extended to more attainable thirty months. In previous work we have displayed a corresponding speed-up effect in childbearing for Swedish-born women. This change in behavior is of general interest since it is clear evidence of a causal effect of a policy change on childbearing behavior. In the present paper, we study how this change in behavior was adopted in different social strata of the Swedish population. We examine whether the speed-up of childbearing differed by educational attainment and by country of origin, to see whether some social groups reacted faster or more strongly to the policy change than others. We cannot find any important difference in the reaction to the introduction of the “speed premium” between educational groups of Swedish-born parents. Similarly, we find no important difference in the mode of reaction between Swedish-born women and Nordic immigrants to the country. By contrast, immigrants from non-Nordic countries hardly seem to have reacted to the “speed premium”.Sweden, childbearing