7,479 research outputs found
Dark Energy and the Hubble Age
I point out that an effective upper limit of approximately 20 Gyr (for a
Hubble constant of 72 km/s/Mpc) or alternatively on the -independent
quantity , exists on the age of the Universe, essentially
independent of the unknown equation of state of the dominant dark energy
component in the Universe. Unless astrophysical constraints on the age of the
Universe can convincingly reduce the upper limit to below this value no useful
lower limit on the equation of state parameter for this component can be
obtained. Direct dating by stars does not provide a useful constraint, but
model-dependent cosmological limits from supernovae and the CMB observations
may. For a constant value of , a bound Comment: 4 pages, submitted to Ap. J. Lett (analytic asymptotic upper bound
now added
"Just So" Neutrino Oscillations Are Back
Recent evidence for oscillations of atmospheric neutrinos at Super-Kamiokande
suggest, in the simplest see-saw interpretation, neutrino masses such that
`just so' vacuum oscillations can explain the solar neutrino deficit. Super-K
solar neutrino data provide preliminary support for this interpretation. We
describe how the just-so signal---an energy dependent seasonal variation of the
event rate, might be detected within the coming years and provide general
arguments constraining the sign of the variation. The expected variation at
radiochemical detectors may be below present sensitivity, but a significant
modulation in the Be signal could shed light on the physics of the solar
core---including a direct measure of the solar core temperature.Comment: 4 pages, revtex, 4 ps figs: new refs added, and Super-K energy
resolution function incorporate
Capital Jurors in an Era of Death Penalty Decline
The state of public opinion regarding the death penalty has not experienced such flux since the late 1960s. Death sentences and executions have reached their lowest annual numbers since the early 1970s and today, the public appears fairly evenly split in its views on the death penalty. In this Essay, we explore, first, whether these changes in public opinion mean that fewer people will be qualified to serve on death penalty trials as jurors, and second, whether potential jurors are affected by changes in the practice of the death penalty. We conducted surveys of persons reporting for jury duty at the Superior Court of Orange County, California. What we found was surprising. Surveys of jurors in decades past suggested ten to twenty percent of jury-eligible individuals would be excludable due to their substantial doubts about the death penalty. Despite Orange County’s status as a redoubt of death sentencing, we find that 35% or more of jurors reporting for jury service were excludable as having such substantial doubts about the death penalty that it would “substantially impair” their ability to perform their role as jurors. Indeed, large numbers went further: roughly a quarter said they would be reluctant to find a person guilty of capital murder knowing the death penalty was a possibility. A final question asked whether the fact that executions have not been conducted in California for a decade impacts whether jurors would be favorable towards the death penalty. We found that, across all types of attitudes towards the death penalty, that fact made jurors less inclined to sentence a person to death. Rare punishments may seem more arbitrary, even to those who find them morally acceptable. We conclude by describing how this research can be useful for scholars, litigators, and judges concerned with selection of jurors in death penalty cases, and we discuss why, as social and legal practices change, more study of public attitudes towards punishment is needed
Capital Jurors in an Era of Death Penalty Decline
The state of public opinion regarding the death penalty has not experienced such flux since the late 1960s. Death sentences and executions have reached their lowest annual numbers since the early 1970s and today, the public appears fairly evenly split in its views on the death penalty. In this Essay, we explore, first, whether these changes in public opinion mean that fewer people will be qualified to serve on death penalty trials as jurors, and second, whether potential jurors are affected by changes in the practice of the death penalty. We conducted surveys of persons reporting for jury duty at the Superior Court of Orange County, California. What we found was surprising. Surveys of jurors in decades past suggested ten to twenty percent of jury-eligible individuals would be excludable due to their substantial doubts about the death penalty. Despite Orange County’s status as a redoubt of death sentencing, we find that 35% or more of jurors reporting for jury service were excludable as having such substantial doubts about the death penalty that it would “substantially impair” their ability to perform their role as jurors. Indeed, large numbers went further: roughly a quarter said they would be reluctant to find a person guilty of capital murder knowing the death penalty was a possibility. A final question asked whether the fact that executions have not been conducted in California for a decade impacts whether jurors would be favorable towards the death penalty. We found that, across all types of attitudes towards the death penalty, that fact made jurors less inclined to sentence a person to death. Rare punishments may seem more arbitrary, even to those who find them morally acceptable. We conclude by describing how this research can be useful for scholars, litigators, and judges concerned with selection of jurors in death penalty cases, and we discuss why, as social and legal practices change, more study of public attitudes towards punishment is needed
Religion and Intimate Partner Violence in Chile: Macro- and Micro-Level Influences
The Catholic Church has had a strong influence on the Chilean legal and social landscape in ways that have adversely affected victims of intimate partner violence; e.g., it succeeded until just five years ago in blocking efforts to legalize divorce. At the same time, quantitative studies based on survey data from the United States and other countries show a generally favorable influence of religion on health and many other domains of life, including intimate partner violence. The present study explores the puzzle posed by these seemingly opposing macro- and micro- level forces. Results based on data from the 2005 Survey of Student Well-Being, a questionnaire on gender based violence administered to students at a large public university in Chile, show that moderate or low levels of religiosity are associated with reduced vulnerability to violence, but high levels are not. This non-linearity sheds light on the puzzle, because at the macro level the religious views shaping Chile's legal and social environment have been extreme.intimate partner violence, religion
Observation of Cosmic Acceleration and Determining the Fate of the Universe
Current observations of Type Ia supernovae provide evidence for cosmic
acceleration out to a redshift of z \lsim 1, leading to the possibility that
the universe is entering an inflationary epoch. However, inflation can take
place only if vacuum-energy (or other sufficiently slowly redshifting source of
energy density) dominates the energy density of a region of physical radius
1/H. We argue that for the best-fit values of and
inferred from the supernovae data, one must confirm cosmic acceleration out to
at least to infer that the universe is inflating.Comment: 4 pages;important changes in conclusion; published in Phys. Rev. Let
Geometry and Destiny
The recognition that the cosmological constant may be non-zero forces us to
re-evaluate standard notions about the connection between geometry and the fate
of our Universe. An open Universe can recollapse, and a closed Universe can
expand forever. As a corollary, we point out that there is no set of
cosmological observations we can perform that will unambiguously allow us to
determine what the ultimate destiny of the Universe will be.Comment: 7 pages, Gravity Research Foundation Essa
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