Discrete Spacetime and Relativistic Quantum Particles

We study a single quantum particle in discrete spacetime evolving in a causal way. We see that in the continuum limit any massless particle with a two dimensional internal degree of freedom obeys the Weyl equation, provided that we perform a simple relabeling of the coordinate axes or demand rotational symmetry in the continuum limit. It is surprising that this occurs regardless of the specific details of the evolution: it would be natural to assume that discrete evolutions giving rise to relativistic dynamics in the continuum limit would be very special cases. We also see that the same is not true for particles with larger internal degrees of freedom, by looking at an example with a three dimensional internal degree of freedom that is not relativistic in the continuum limit. In the process we give a formula for the Hamiltonian arising from the continuum limit of massless and massive particles in discrete spacetime.Comment: 6 page

Causal Fermions in Discrete Spacetime

In this paper, we consider fermionic systems in discrete spacetime evolving with a strict notion of causality, meaning they evolve unitarily and with a bounded propagation speed. First, we show that the evolution of these systems has a natural decomposition into a product of local unitaries, which also holds if we include bosons. Next, we show that causal evolution of fermions in discrete spacetime can also be viewed as the causal evolution of a lattice of qubits, meaning these systems can be viewed as quantum cellular automata. Following this, we discuss some examples of causal fermionic models in discrete spacetime that become interesting physical systems in the continuum limit: Dirac fermions in one and three spatial dimensions, Dirac fields and briefly the Thirring model. Finally, we show that the dynamics of causal fermions in discrete spacetime can be efficiently simulated on a quantum computer.Comment: 16 pages, 1 figur

Choosing a Cigarette Brand: Determining the Value of Countermarketing Information to Smokers Using Field Auctions

Information about cigarettes can help smokers come to an informed decision about what cigarettes to purchase. Countermarketing information can help smokers make informed decisions, but little is known about the value of this information to smokers. In this article, we use data from experimental auctions to estimate the value of countermarketing information that counters industry claims about reduced-risk cigarettes. We find that this information has significant value to smokers who have been exposed to marketing information from tobacco companies touting reduced-risk cigarettes, but we find no evidence it provides value to smokers not exposed to this marketing information.experimental auctions, field experiments, Consumer/Household Economics, Demand and Price Analysis, C93, M31,

The Value of Countermarketing Information to Smokers: Evidence from Field Auctions

Information about cigarettes can help smokers come to an informed decision about what cigarettes to purchase. Countermarketing information, which helps counter potentially biased marketing information, can fill this void, but little is known about the value of this information to smokers. In this paper, we use data from experimental auctions to estimate the value of countermarketing information to smokers. We find that countermarketing information has significant value to smokers who have been exposed to marketing information from tobacco companies, but we find no evidence it provides value to smokers not exposed to marketing informationfield auctions, value of information, cigarettes, Consumer/Household Economics, Health Economics and Policy,

The Impact of Tobacco Control Program Expenditures on Aggregate Cigarette Sales: 1981-1998

Since the 1998 Master Settlement Agreement between states and the tobacco industry, states have unprecedented resources for programs to reduce tobacco use. Decisions concerning the use of these funds will, in part, be based on the experiences of states with existing programs. We review the experiences of several states that have adopted comprehensive tobacco control programs. We also report estimates from econometric analyses of the impact of tobacco control expenditures on aggregate tobacco use in all states and in selected states with comprehensive programs for the period from 1981 through 1998. Our analyses clearly show that increases in funding for state tobacco control programs reduce tobacco use.

Chapter Polystyrene as Hazardous Household Waste

During the Humanitarian‐demining actions, teleoperation of sensors or multi‐sensor heads can enhance-detection process by allowing more precise scanning, which is useful for the optimization of the signal processing algorithms. This chapter summarizes the technologies and experiences developed during 16 years through national and/or European‐funded projects, illustrated by some contributions of our own laboratory, located at the Royal Military Academy of Brussels, focusing on the detection of unexploded devices and the implementation of mobile robotics systems on minefields

Polystyrene as Hazardous Household Waste

Polystyrene (PS) is a petroleum‐based plastic made from styrene (vinyl benzene) monomer. Since it was first commercially produced in 1930, it has been used for a wide range of commercial, packaging and building purposes. In 2012, approximately 32.7 million tonnes of styrene were produced globally, and polystyrene is now a ubiquitous household item worldwide. In 1986, the US Environmental Protection Agency (EPA) announced that the polystyrene manufacturing process was the fifth largest source of hazardous waste. Styrene has been linked to adverse health effects in humans, and in 2014, it was listed as a possible carcinogen. Yet, despite mounting evidence and public concern regarding the toxicity of styrene, the product of the polymerisation of styrene, PS, is not considered hazardous. This chapter draws on a series of movements called the ‘new materialisms’ to attend to the relational, unstable and contingent nature of PS, monomers and other additives in diverse environments, and thus, we highlight the complexities involved in the categorisation of PS as ‘hazardous’ and the futility of demarcating PS as ‘household waste\u27. While local examples are drawn from the New Zealand context, the key messages are transferrable to most policy contexts and diverse geographical locations