Holographic Magnetic Star

A warm fermionic AdS star under a homogeneous magnetic field is explored. We obtain the relativistic Landau levels by using Dirac equation and use the Tolman-Oppenheimer-Volkoff (TOV) equation to study the physical profiles of the star. Bulk properties such as sound speed, adiabatic index, and entropy density within the star are calculated analytically and numerically. Bulk temperature increases the mass limit of the AdS star but external magnetic field has the opposite effect. The results are partially interpreted in terms of the pre-thermalization process of the gauge matter at the AdS boundary after the mass injection. The entropy density is found to demonstrate similar temperature dependence as the magnetic black brane in the AdS in certain limits regardless of the different nature of the bulk and Hawking temperatures. Total entropy of the AdS star is also found to be an increasing function of the bulk temperature and a decreasing function of the magnetic field, similar behaviour to the mass limit. Since both total entropy and mass limit are global quantities, they could provide some hints to the value of entropy and energy of the dual gauge matter before and during the thermalization.Comment: 39 pages, 14 figures, 1 table, comments and references added, to appear in JHE

Quantum probability: A new method for modelling travel behaviour

There has been an increasing effort to improve the behavioural realism of mathematical models of choice, resulting in efforts to move away from random utility maximisation (RUM) models. Some new insights have been generated with, for example, models based on random regret minimisation (RRM, μ-RRM). Notwithstanding work using for example Decision Field Theory (DFT), many of the alternatives to RUM tested on real-world data have however only looked at only modest departures from RUM, and differences in results have consequently been small. In the present study, we address this research gap again by investigating the applicability of models based on quantum theory. These models, which are substantially different from the state-of-the-art choice modelling techniques, emphasise the importance of contextual effects, state dependence, interferences and the impact of choice or question order. As a result, quantum probability models have had some success in better explaining several phenomena in cognitive psychology. In this paper, we consider how best to operationalise quantum probability into a choice model. Additionally, we test the quantum model frameworks on a best/worst route choice dataset and demonstrate that they find useful transformations to capture differences between the attributes important in a most favoured alternative compared to that of the least favoured alternative. Similar transformations can also be used to efficiently capture contextual effects in a dataset where the order of the attributes and alternatives are manipulated. Overall, it appears that models incorporating quantum concepts hold significant promise in improving the state-of-the-art travel choice modelling paradigm through their adaptability and efficient modelling of contextual changes

A Comprehensive Modeling Procedure for the Human Granulopoietic System: Over-all View and Summary of Data

Abstract Understanding of the granulopoietic system in both normal and diseased states might be assisted by the use of a quantitative modeling procedure that relates the underlying cellular events of granulopoiesis studied in the laboratory to the marrow and peripheral blood picture as it might be seen in the clinic. In this way, the modeling procedure could become both an adjunct to ongoing laboratory research, as well as a means for rationally deciding on modes of treatment for pathologic conditions. The depth and rapid pace of modern granulopoietic research require that the modeling procedure be, on the one hand, detailed enough to permit the inclusion of the pertinent events at the cellular level as they are known today, while on the other hand, remain flexible enough to permit both the modification of any part and the possibility of seeing the predicted consequences of this modification for both the normal and diseased states. A detailed procedure was developed for an hour-by-hour description of the interrelationship of the kinetics of the various marrow cell types with the events in the peripheral blood and tissue spaces. The model was extended to include the toxic effects of a drug (5-fluorouracil) administered according to the protocol of an actual trial with cancer patients, and the temporal pattern of the predicted effects of the drug on the peripheral blood count was compared with that found in the clinic.</jats:p