325 research outputs found
The top squark-mediated annihilation scenario and direct detection of dark matter in compressed supersymmetry
Top squark-mediated annihilation of bino-like neutralinos to top-antitop
pairs can play the dominant role in obtaining a thermal relic dark matter
abundance in agreement with observations. In a previous paper, it was argued
that this can occur naturally in models of compressed supersymmetry, which
feature a running gluino mass parameter that is substantially smaller than the
wino mass parameter at the scale of apparent gauge coupling unification. Here I
study in some more detail the parameter space in which this is viable, and
compare to other scenarios for obtaining the observed dark matter density. I
then study the possibility of detecting the dark matter directly in future
experiments. The prospects are consistently very promising for a wide variety
of model parameters within this scenario.Comment: 17 pages. v2: additions to figures 4 and
Designing Incentives in Startup Teams: Form and Timing of Equity Contracting
Entrepreneurial teams assign equity positions in their startups using a term sheet that details equity splits and conditions for being granted those splits. It is conventional wisdom in the entrepreneurial press that equal splits are poor choices. The conventional logic is that by not connecting rewards to contribution level equal split contracts can encourage free-riding behaviors. We experimentally test this conventional wisdom, among other entrepreneurial contracting hypotheses. Our results confirm the relationship between equal splits and depressed effort and contribution, but suggest a different causal sequence relative to conventional wisdom. Rather than the contract form being the primitive and the behavior the derived consequence, our results suggest the reverse. The differences in contract performance are driven primarily by the sorting of high contributors into non-equal contracts and of low contributors into equal contracts. However, delaying the contracting mitigates these sorting effects, reducing the effort gap between contracts. Taken together, our results suggest that both investors and founders should pay as much (or more) attention to personality type as they do to contract form, but if one is stuck with a given set of personalities delayed contracting (more so than contract form) can improve performance.https://deepblue.lib.umich.edu/bitstream/2027.42/138118/1/1372_Kagan.pd
Acceptance of Automated Vehicles: Case Study of Drive2theFuture Project
The transport sector has increased awareness regarding automated vehicles and their integration to reduce impacts by increasing efficiency. This paper aims to identify correlation parameters of acceptance by a pre-acceptance analysis questionnaire done by the Drive2theFuture project. To reach this, an acceptance interested questionnaire has considered determining the acceptance correlated parameters with also regression analysis and cross-cutting comparisons.
The result of the study indicates a well-balanced connection with the users’ characteristics, in terms of knowledge, perception, education level, income, and privacy concerns has a positive increase of acceptance with slight significance. Then, the correlation analysis shows acceptance is more related to education, risks, and previous knowledge of automated vehicles. So, training and interactions would increase acceptanc
Environmental Enrichment in Kennelled Pit Bull Terriers (Canis lupus familiaris)
Although social enrichment can be considered beneficial in helping dogs cope with the kennel environment, when taking individual needs into account, it places a large demand on the carers and may not be appropriate in under-resourced kennels. Some kennels are also designed in such a way that there is too much social interaction, in that individuals cannot choose to distance themselves from conspecifics. This study therefore aimed to assess the effects of easily accessible enrichment on the behaviour of kennelled Pit Bull Terrier type dogs rescued from a dog-fighting ring in the Philippines. Thirty-six dogs were allocated to one of three treatment groups following a matched-subject design: (i) cardboard bed provision; (ii) coconut provision; and (iii) visual contact with dogs housed in adjacent cages obstructed with cardboard partitions. Behavioural diversity and the duration and frequency of individual behaviours were analysed using linear mixed-effect models. Yawning frequencies and time spent lying down and sitting decreased during treatment. No particular treatment was more influential in these behavioural changes. In conclusion, enrichment, regardless of type, affected the dogs’ behaviour, with some effects depending on the sex of the dogs. Therefore, it is possible to cheaply and sustainably enrich the lives of dogs living in highly constrained environments, however, further research is required to refine the methods used
In Memoriam: Clark Byse
The editors of the Harvard Law Review respectfully dedicate this issue to Professor Clark Byse
Coherent dynamics of Bose-Einstein condensates in high-finesse optical cavities
We study the mutual interaction of a Bose-Einstein condensed gas with a
single mode of a high-finesse optical cavity. We show how the cavity
transmission reflects condensate properties and calculate the self-consistent
intra-cavity light field and condensate evolution. Solving the coupled
condensate-cavity equations we find that while falling through the cavity, the
condensate is adiabatically transfered into the ground state of the periodic
optical potential. This allows time dependent non-destructive measurements on
Bose-Einstein condensates with intriguing prospects for subsequent controlled
manipulation.Comment: 5 pages, 5 figures; revised version: added reference
For and against ownership: William Godwin's theory of property
© 2009 University of Notre Dame. 12 month embargo by the publisher. Article will be released in April 2010.This article offers an interpretation of British philosopher William Godwin's theory of property ownership, as outlined in his Enquiry Concerning Political Justice. Godwin's work can be read as presenting an incoherent account of property rights, which, on the one hand, justifies its existence on seemingly utilitarian grounds while, on the other, impugns its legitimacy on egalitarian grounds. But the contradiction apparent in Godwin's position is actually illusory and can in fact be plausibly interpreted as comprising a coherent two-level understanding of political morality, wherein the right to own private property is best comprehended as a “right to do wrong.
Phase separation at all interaction strengths in the t-J model
We investigate the phase diagram of the two-dimensional t-J model using a
recently developed Green's Function Monte Carlo method for lattice fermions. We
use the technique to calculate exact ground-state energies of the model on
large lattices. In contrast to many previous studies, we find the model phase
separates for all values of J/t. In particular, it is unstable at the hole
dopings and interaction strengths at which the model was thought to describe
the cuprate superconductors.Comment: Revtex, 4 pages, 3 figures. Some minor changes were made to the text
and figures, and some references were adde
- …