1,131 research outputs found
SAN JERÓNIMO, Epistolano. Edición bilingüe I, traducción, introducciones y notas por Juan Bautista Valero, Ed. Católica (B. A. C. 530), Madrid 1993, 910 pp., 13 x 20. [RECENSIÓN]
The young HD 73583 (TOI-560) planetary system :two 10-M<sub>⊕</sub> mini-Neptunes transiting a 500-Myr-old, bright, and active K dwarf
WKB formalism and a lower limit for the energy eigenstates of bound states for some potentials
In the present work the conditions appearing in the WKB approximation
formalism of quantum mechanics are analyzed. It is shown that, in general, a
careful definition of an approximation method requires the introduction of two
length parameters, one of them always considered in the text books on quantum
mechanics, whereas the second one is usually neglected. Afterwards we define a
particular family of potentials and prove, resorting to the aforementioned
length parameters, that we may find an energy which is a lower bound to the
ground energy of the system. The idea is applied to the case of a harmonic
oscillator and also to a particle freely falling in a homogeneous gravitational
field, and in both cases the consistency of our method is corroborated. This
approach, together with the Rayleigh--Ritz formalism, allows us to define an
energy interval in which the ground energy of any potential, belonging to our
family, must lie.Comment: Accepted in Modern Physics Letters
Essays on environmentally friendly behaviour and environmental policy
The thesis consists of three chapters of self-contained studies.
In Chapter 1, I examine the decision of individuals to secure the provision of an
environmental service under a Psychological Games framework. Since environmental
services are considered public goods, there is an ongoing depletion of natural resources.
While standard economic theory predicts the introduction of a PES is supposed to
correct the associated externality by establishing a market which offers a monetary
compensation to owners of vital natural resources as a recognition of their effort in
providing the environmental services, this chapter argues such intervention might
backfire: a motivation crowding-out arises if individuals believe others reciprocate
friendly behaviour solely to receive the monetary compensation, ultimately decreasing
total environmental protection. Even if environmental protection does take place, the
motivation of individuals to secure the provision of the environmental service becomes
commodified by the PES. Finally, awarding the PES only to a subset of individuals will
also have negative effects on environmental protection, since those not receiving the
PES will not want to do for free something that others are being paid to do.
Environmental policy implications of this economic instrument are further discussed.
In Chapter 2, a sample of the World Values Survey dataset is analyzed to show
there are substantial behavioural differences between immigrants and native-born
regarding pro-environmental action. In particular, while neither native-born nor
immigrants are more willing to sacrifice money to save the environment, immigrants
actually engage more on activities like choosing products that are better for the
environment, recycling, and reducing water consumption. The engagement in proenvironmental
behaviour of immigrants is region-specific and depends on their source
region. Moreover, such relatively higher actual engagement in environmentally friendly
behaviours can be explained by their high socio-economic status and their high
education level, i.e. “selective immigration”. When the behaviour of immigrants by
their length of residence in the host country is analyzed, no differences in proenvironmental
attitudes or pro-environmental behaviour are found, a result which
suggests they do not develop a “sense of belongingness” to the host country. Finally, in
line with the standard finding in the literature of acculturation in environmental
behaviour, this chapter finds that immigrants conform through time to some of the proenvironmental
actions of native-born.
In Chapter 3, I investigate the indirect effects on norm activation produced by
monetary environmental policy instruments which introduce a situational cue that
fosters a change of identity among individuals with potential negative consequences on
their pro-environmental behaviour. For that purpose, a two-period identity selection
model based on self-verification theory is developed. In each period there are two types
of selves an individual can adopt: selfish and pro-environmental. The process of identity
selection is driven by the desire of individuals to be consistent across the two periods in
order to avoid social disapproval due to self-change. Results show that the monetary
environmental policy introduces an asymmetry in the identity selection process that
produces a failure of norm activation: while selfish agents preserve their selfish identity
after the policy is implemented, pro-environmental agents might change their identity
despite they experience social disapproval due to a reduction in the cognitive benefits of
keeping such identity produced by the monetary component of the policy. Implications
for environmental policy design are discussed
Bouncing Cosmologies in Palatini Gravity
We consider the early time cosmology of f(R) theories in Palatini formalism
and study the conditions that guarantee the existence of homogeneous and
isotropic models that avoid the Big Bang singularity. We show that for such
models the Big Bang singularity can be replaced by a cosmic bounce without
violating any energy condition. In fact, the bounce is possible even for
pressureless dust. We give a characterization of such models and discuss their
dynamics in the region near the bounce. We also find that power-law lagrangians
with a finite number of terms may lead to non-singular universes, which
contrasts with the infinite-series Palatini f(R) lagrangian that one needs to
fully capture the effective dynamics of Loop Quantum Cosmology. We argue that
these models could also avoid the formation of singularities during stellar
gravitational collapse.Comment: 8 pages, 4 figures; added references and a short comment in sec.I
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