1,477 research outputs found
High Scale Boundary Conditions in Models with Two Higgs Doublets
We investigate high scale boundary conditions on the quartic Higgs-couplings
and their -functions in the Type-II Two Higgs Doublet Model and the
Inert Doublet Model. These conditions are associated with two possible UV
physics scenarios: the Multiple Point Principle, in which the potential
exhibits a second minimum at , and Asymptotic Safety, where the scalar
couplings run towards an interacting UV fixed point at high scales. We employ
renormalisation group running at two-loops and apply theoretical and
experimental constraints to their parameter spaces. We find neither model can
simultaneously accommodate the MPP whilst also providing realistic masses for
both the Higgs and the top quark. However, we do find regions of parameter
space compatible with Asymptotic Safety.Comment: 25 pages, 13 figures (25 plots); v3: version accepted for publicatio
A new species of mudfish, Neochanna (Teleostei: Galaxidae), from northern New Zealand
A new species of mudfish, Neochanna, is described from Northland. Neochanna heleios n.sp. is known from only three ephemeral wetland sites on the Kerikeri volcanic plateau and is abundant only at the type locality. The new species has a head resembling that of the brown mudfish, Neochanna apoda, and a caudal region resembling that of the black mudfish, Neochanna diversus. It can be distinguished from all Neochanna species in having a reduced number of principal caudal fin rays (13 or less). Morphometric and meristic comparisons with N. apoda and N. diversus are provided
New conception of the function of the general vasodilator reflexes
A survey of the literature regarding the vasodepressor
and cardiodepressor reflexes is given.
Evidence is put forward that the impulses which
arise from the cardioaortic and carotid sinus regions
control not only the normal vagus restraint of the
heart but also the capacity of the circulation. Loss
of these impulses not only causes cardiac acceleration
but results in an increased return of venous blood
to the heart.
It is shown that conditions which are believed
to be produced in exercise and which are known to
reduce the vagus restraint of the heart at the same
time reduce the effect of the carotid sinus impulses
upon the vessels.
The view is therefore put forward that an
important function of the vasodepressor reflxes
is to control the capacity of the circulation in
order to provide a reserve of blood for use in
physical exercise, just as is provided a cardiac
reserve to deal with such blood maintained by
similar reflex mechanisms.
The possible clinical significance of the
findings is indicated, and a bibliography of the
literature referred to in the text is given
High scale boundary conditions with an additional complex singlet
We investigate Planck-scale boundary conditions on Higgs quartic interactions and their
β
functions in the Standard Model augmented by an additional complex scalar. We use renormalization group running at two loops, and include both theoretical and experimental constraints. We find that the boundary condition
λ
=
β
λ
=
0
at the Planck scale is compatible with the current Higgs and top mass measurements, but requires additional scalars lighter than about 600 GeV
Implementation of the FAA research and development electromagnetic database
The Idaho National Engineering Laboratory (INEL) has been assisting the FAA in developing a database of information about lightning. The FAA Research and Development Electromagnetic Database (FRED) will ultimately contain data from a variety of airborne and ground-based lightning research projects. An outline of the data currently available in FRED is presented. The data sources which the FAA intends to incorporate into FRED are listed. In addition, it describes how the researchers may access and use the FRED menu system
Energy scenario choices: insights from a retrospective review of UK energy futures
Since the 1980s, there has been a shift in energy research. It has shifted from approaches that forecast or project the future to approaches which make more tentative claims and which explore several plausible scenarios. Due to multiple uncertainties in energy systems, there is an infinite amount of plausible scenarios that could be constructed and scenario developers therefore choose smaller, more tangible sets of scenarios to analyse. Yet, it is often unclear how and why this scenario choice is made and how such choices might be improved. This paper presents a retrospective analysis of twelve UK energy scenarios developed between 1978 and 2002. It investigates how specific scenarios were chosen and whether these choices captured the actual UK energy system transition. It finds that scenario choice reflected contemporary debates, leading to a focus on certain issues and limiting the insights gleaned from these exercises. The paper argues for multi-organisation and multi-method approaches to the development of energy scenarios to capture the wide range of insights on offer. Rather than focus on uncertainty in model parameters, greater reflection on structural uncertainties, such as shifts in energy governance, is also required
Mapping regional vulnerability in Europe’s energy transition: development and application of an indicator to assess declining employment in four carbon-intensive industries
Europe’s transition to an energy system compatible with limiting global heating to 1.5 °C will require radical changes in energy systems. While this will create substantial new growth industries in clean technologies, some currently important economic activities will decline. The impacts of that transition will not be the same for all regions. We map the economic vulnerability of European regions to ambitious decarbonisation scenarios in terms of employment losses in four carbon-intensive industries. To do so, we develop a composite vulnerability indicator that combines each region’s share of employment in those high-carbon industries with other dimensions of vulnerability and resilience. We then explore how regional patterns of vulnerability are influenced by the technology pathway to 2050, using four scenarios modelled using the European PRIMES model. We show that economic vulnerability to the low-carbon transition is regionally concentrated, with some regions combining high employment shares in industries expected to decline with weak adaptive capacity and high pre-existing unemployment. We also show that there is little variation in regional vulnerability arising from different transition pathways. All scenarios compatible with 1.5 °C involve large declines in all high-carbon sectors we analyse, and as a result, scenario variation does not lead to large variation in relative vulnerability of regions. The results highlight regions that may be in need of additional policy support to diversify their economies and achieve a just transition
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