Metallic phase in the two-dimensional ionic Hubbard model

We investigate the phases of the ionic Hubbard model in a two-dimensional square lattice using determinant quantum Monte Carlo (DQMC). At half-filling, when the interaction strength or the staggered potential dominate we find Mott and band insulators, respectively. When these two energies are of the same order we find a metallic region. Charge and magnetic structure factors demonstrate the presence of antiferromagnetism only in the Mott region, although the externally imposed density modulation is present everywhere in the phase diagram. Away from half-filling, other insulating phases are found. Kinetic energy correlations do not give clear signals for the existence of a bond-ordered phase

Probing neutrino physics with a self-consistent treatment of the weak decoupling, nucleosynthesis, and photon decoupling epochs

We show that a self-consistent and coupled treatment of the weak decoupling, big bang nucleosynthesis, and photon decoupling epochs can be used to provide new insights and constraints on neutrino sector physics from high-precision measurements of light element abundances and cosmic microwave background observables. Implications of beyond-standard-model physics in cosmology, especially within the neutrino sector, are assessed by comparing predictions against five observables: the baryon energy density, helium abundance, deuterium abundance, effective number of neutrinos, and sum of the light neutrino mass eigenstates. We give examples for constraints on dark radiation, neutrino rest mass, lepton numbers, and scenarios for light and heavy sterile neutrinos.Comment: 29 pages, 10 figure

Tourism and the challenge of Arctic governance

This paper explores the relationship between tourism and the challenges of governance in the Arctic region. Recently, both political and academic interest in the Arctic has been on the rise as a result of the increasing geopolitical importance of the region. Changes of the climatic conditions and melting of the Arctic ice caps have resulted in increased access to the “world´s last wilderness”. The increased access and interest are contributing to a growing number of tourists visiting the North. As yearly arrivals continue to rise, a number of problematic issues need to be addressed. This paper reviews the main instruments relevant to the discussion of tourism currently employed in the governance of the Arctic, and critically evaluates the insufficiencies of the current legal framework for Arctic governance and regulation of tourism in the Arctic. It concludes that although tourism in the Arctic has a number of advantages, particularly for the indigenous populations, the current legal and regulatory framework in the region lacks the scope and authority to minimize the potential (and increasing) environmental, economic, and social risks associated with increased tourism and other human activity in the region

Evolution of twin-beam in active optical media

We study the evolution of twin-beam propagating inside active media that may be used to establish a continuous variable entangled channel between two distant users. In particular, we analyze how entanglement is degraded during propagation, and determine a threshold value for the interaction time, above which the state become separable, and thus useless for entanglement based manipulations. We explicitly calculate the fidelity for coherent state teleportation and show that it is larger than one half for the whole range of parameters preserving entanglemenent.Comment: several misprints correcte

Quantum Monte Carlo Study of an Interaction-Driven Band Insulator to Metal Transition

We study the transitions from band insulator to metal to Mott insulator in the ionic Hubbard model on a two dimensional square lattice using determinant Quantum Monte Carlo. Evaluation of the temperature dependence of the conductivity demonstrates that the metallic region extends for a finite range of interaction values. The Mott phase at strong coupling is accompanied by antiferromagnetic (AF) order. Inclusion of these intersite correlations changes the phase diagram qualitatively compared to dynamical mean field theory.Comment: 4 pages, 6 figure

Managerial cognition and the value chain in the digital music industry

Do entrepreneurs construct new cognitive frameworks or adapt existing ones in unstable, transforming industry contexts, and what importance do existing mental models, in particular the value chain, take on for them? The official discourses, mission and vision statements of the 21 most visible online music ventures were analyzed using mixed methods to capture the representations of the digital music industry of the entrepreneurs at their helm. The managerial cognition of digital music entrepreneurs challenges all the dominant logics and industry recipes of the traditional music industry and encounters no cognitive barriers. The cognitive frame of the value chain remains prevalent however in the representations of digital music entrepreneurs, and restrains them from embracing the specificities of the creative industries

Tourists perceptions of climate change in Cairns, Australia

This paper will briefly review the impacts of climate change on the Wet Tropics and the Great Barrier Reef, and then will discuss the results of an exploratory study into tourists perceptions of 1) the impact of climate change on the Wet Tropics and Great Barrier Reef and the tourism industry in Cairns, and 2) what tourists can do to mitigate these impacts. A survey was administered to 81 tourists in Cairns, Australia. The results suggest that tourists have a range of outlooks concerning the impact of climate change in Cairns and the role of tourists in mitigating these impacts

Evaluating tourism community preferences

A short online survey of Kingman Arizona residents included two approaches for determining the relative importance of social, cultural, environmental, and economic attributes to community quality of life. A simple multiattribute choice approach gave noticeably different results from a standard independent attribute ranking approach and lead researchers to recommend socially oriented tourism development projects over economically oriented ones

Arab women employment in the United Arab Emirates: exploring opportunities, motivations and challenges

This research paper identifies and explores the challenges and barriers that Arab women in the United Arab Emirates (UAE) face in their careers. Primary data was collected via an interview process involving 12 Arab women who reside and work in senior decision making positions in the UAE. Taking into account an overview of the global and UAE-specific challenges faced by women in the workplace and considering the significant efforts of the UAE government to promote women in leadership, as reported in literature, the analysis revealed that women often navigated their career through a sub-text of deep rooted social and cultural values that manifested themselves as stereotypes both in and out of the workplace and that these stereotypes impacted their career trajectory. Main barriers highlighted include; unfavourable policies, work/family conflicts and lack of support and options for entrepreneurial activity. The recommendations at the end of the paper focus on the need for continued government and institutional support in an effort to break down and change societal perceptions of Arab women who want to pursue a career