Jet quenching of massive quarks in a nuclear medium

Utilizing the generalized factorization of twist-4 processes, we derive the modified heavy quark fragmentation function after considering the gluon radiation induced by multiple scattering in DIS. It is found that the mass effects of heavy quark may reduce the gluon formation time and change the medium size dependence of heavy quark energy loss. The radiative energy loss is also significantly suppressed relative to a light quark due to the dead-cone effect.Comment: Talk at the "32nd International Conference on High Energy Physics", August 16 - 22, 2004, Beijing, China. To appear in the proceedings of ICHEP'04. 4 pages, 4 figure

Hyperband wireless

Research at Oxford University is currently exploring the feasibility of this concept with a focus on examining the fundamental aspects such as signal propagation and waveform design. The objective of research proposed here is to compliment the work at Oxford University through addressing ways of managing interference from other spectrum users. This PhD will have collaborative aspects with the Oxford University

Jet tomography of high-energy nucleus-nucleus collisions at next-to-leading order

We demonstrate that jet observables are highly sensitive to the characteristics of the vacuum and the in-medium QCD parton showers and propose techniques that exploit this sensitivity to constrain the mechanism of quark and gluon energy loss in strongly-interacting plasmas. As a first example, we calculate the inclusive jet cross section in high-energy nucleus-nucleus collisions to ${\cal O}(\alpha_s^3)$. Theoretical predictions for the medium-induced jet broadening and the suppression of the jet production rate due to cold and hot nuclear matter effects in Au+Au and Cu+Cu reactions at RHIC are presented.Comment: 4 pages, 3 eps figures, 1 table. As published in PRL

Time Inconsistency, Sophistication, and Commitment An Experimental Study

We experimentally study the relationship between time inconsistency, sophistication about time inconsistency, and self-commitment. Previous research has interpreted demand for commitment devices as evidence for the sophistication of a time-inconsistent decision-maker. In our laboratory experiment, we attempt to measure sophistication directly by way of a cognitive test. We then test the hypothesis that people who are both time-inconsistent and show high cognitive capacity take up commitment devices when offered in the strategic game between their current and their future self. For experimental laboratory commitment choices, we cannot detect a moderating effect of cognition on commitment demand of time-inconsistent subjects. However, we find that the existence of time-inconsistent preferences and sophistication (proxied by cognitive performance) can predict the demand for savings commitment in our hypothetical survey vignette question.Series: Department of Strategy and Innovation Working Paper Serie

Bounds of incidences between points and algebraic curves

We prove new bounds on the number of incidences between points and higher degree algebraic curves. The key ingredient is an improved initial bound, which is valid for all fields. Then we apply the polynomial method to obtain global bounds on $\mathbb{R}$ and $\mathbb{C}$.Comment: 11 page

The determinants of full-service carriers airfares in European hub-to-hub markets

This paper explores the factors influencing the pricing behaviour of full-service carriers in European hub-to-hub markets. Drawing on a 2009 dataset containing route and airfare information, we establish an econometric model to estimate the impact of route structure, alliances, and market concentration on the pricing of European full-service carriers in these markets. The results suggest that alliances on routes connecting two primary hubs, airport concentration, market share inequality and competition from low-cost carriers influence average airfares of full-service carriers in the European hub-to-hub markets

The impact of hub hierarchy and market competition on airfare pricing in US hub-to-hub markets

Over the past years, full-service carriers in Europe have deployed multi-hub-and-spoke systems by joining alliances to exploit network economies. The concentration of flights on a small group of airports leads to the emergence of ‘fortress hubs’ and subsequently creates hub-to-hub markets in Europe reminiscent of the US aviation market. This paper explores the factors influencing the pricing behaviour of full-service carriers in European hub-to-hub markets. Drawing on a 2009 dataset containing route and airfare information, we establish an econometric model to estimate the impact of route structure, alliances, and market concentration on the pricing of European full-service carriers in these markets. Three types of hubs (i.e., primary, secondary and tertiary hubs) are hereby identified to investigate the route structure within the hub-to-hub network. The stepwise regression results suggest that alliances on routes connecting two primary hubs, market share inequality and competition from low-cost carriers influence average airfares of full-service carriers in the European hub-to-hub markets

Dynamics in the European Air Transport Network, 2003-9 : an explanatory framework drawing on stochastic actor-based modeling

In this paper, we outline and test an explanatory framework drawing on stochastic actor-based modeling to understand changes in the outline of European air transport networks between 2003 and 2009. Stochastic actor-based models show their capabilities to estimate and test the effect of exogenous and endogenous drivers on network changes in this application to the air transport network. Our results reveal that endogenous structural effects, such as transitivity triads, indirect relations and betweenness effects impact the development of the European air transport network in the period under investigation. In addition, exogenous nodal and dyadic covariates also play a role, with above all the enlargement of the European Common Aviation Area having benefitted its new members to open more air routes between them. The emergence of major low-cost airline-focused airports also significantly contributed to these changes. We conclude by outlining some avenues for further research