Search results for "Theoretical physics"
showing 10 items of 751 documents
Slinky inflation
2005
We present a new approach to quintessential inflation, in which both dark energy and inflation are explained by the evolution of a single scalar field. We start from a simple scalar potential with both oscillatory and exponential behavior. We employ the conventional reheating mechanism of new inflation, in which the scalar decays to light fermions with a decay width that is proportional to the scalar mass. Because our scalar mass is proportional to the Hubble rate, this gives adequate reheating at early times while shutting off at late times to preserve quintessence and satisfy nucleosynthesis constraints. We discuss a simple model which solves the horizon, flatness, and "why now" problems.…
Minimal noncanonical cosmologies
2006
We demonstrate how much it is possible to deviate from the standard cosmological paradigm of inflation-assisted LambdaCDM, keeping within current observational constraints, and without adding to or modifying any theoretical assumptions. We show that within a minimal framework there are many new possibilities, some of them wildly different from the standard picture. We present three illustrative examples of new models, described phenomenologically by a noncanonical scalar field coupled to radiation and matter. These models have interesting implications for inflation, quintessence, reheating, electroweak baryogenesis, and the relic densities of WIMPs and other exotics.
An experimentalist point of view on quantitative elaboration of theoretical models
1980
Abstract In a number of problems of solute–solute–solvent interaction, information on the geometrical structure of solvent in the near neighborhood of solute is now available. This was obtained from a variety of experiments as well as from numerical calculations. The present trend in computer simulation as well as an experimental techniques seems to appropriately be towards an extension of this information to include thermal disorder. Despite these efforts, other aspects of solute–solute–solvent interaction do not seem likely to find exhaustive answers through a study of the geometrical configurations of solvent molecules around the solute. More detailed calculations of inter- and intra-mol…
Spin‐Crossover Complexes
2013
EurJIC is proud to present a bumper issue on Spin-Crossover Complexes. Our Guest Editors, Keith Murray, Hiroki Oshio and Jose Antonio Real, have worked hard to put together a fantastic issue. With a valuable personal account of the field by Philipp Gutlich and inspiring papers by leading experts, you will not be disappointed.
A new lattice action for studying topological charge
1996
We propose a new lattice action for non-abelian gauge theories, which will reduce short-range lattice artifacts in the computation of the topological susceptibility. The standard Wilson action is replaced by the Wilson action of a gauge covariant interpolation of the original fields to a finer lattice. If the latter is fine enough, the action of all configurations with non-zero topological charge will satisfy the continuum bound. As a simpler example we consider the $O(3)$ $\sigma$-model in two dimensions, where a numerical analysis of discretized continuum instantons indicates that a finer lattice with half the lattice spacing of the original is enough to satisfy the continuum bound.
Relation Between the State of a System as Isolated and as Open
2020
We discuss the differences in considering the description of a system as isolated or as a subsystem of a wider isolated system. In the latter case, a description in terms of a density operator directly arises without involving probability concepts, but as an orbit invariant. The non-probabilistic physical interpretation of the density operator is mathematically discussed.
Supersymmetric Indices of 3d S-fold SCFTs
2019
Enhancement of global symmetry and supersymmetry in the infrared is one of the most intriguing phenomena in quantum field theory. We investigate such phenomena in a large class of three dimensional superconformal field theories, known as the S-fold SCFTs. Supersymmetric indices are computed for a number of theories containing small rank gauge groups. It is found that indices of several models exhibit enhancement of supersymmetry at the superconformal fixed point in the infrared. Dualities between S-fold theories that have different quiver descriptions are also analysed. We explore a new class of theories with a discrete global symmetry, whose gauge symmetry in the quiver has a different glo…
What is a physical measure of spatial inhomogeneity comparable to the mathematical approach?
1999
A linear transformation f(S) of configurational entropy with length scale dependent coefficients as a measure of spatial inhomogeneity is considered. When a final pattern is formed with periodically repeated initial arrangement of point objects the value of the measure is conserved. This property allows for computation of the measure at every length scale. Its remarkable sensitivity to the deviation (per cell) from a possible maximally uniform object distribution for the length scale considered is comparable to behaviour of strictly mathematical measure h introduced by Garncarek et al. in [2]. Computer generated object distributions reveal a correlation between the two measures at a given l…
The Poetics of the Hypercycle in Mircea Cărtărescu’s Solenoid
2020
This essay analyses the most recent novel of Romanian author Mircea Cartarescu (Solenoid, 2015). To this end, I will use a specific extension of career construction theory in the field of literary ...
Minkowski-Lorentz Spaces Applications: Resolution of Apollonius and Dupin Problems
2019
International audience