2,928 research outputs found
Enhancing Christian School Experiences for Pre-Service Teachers through Service-Learning Partnerships
The mission of the Teacher Licensure Program at Liberty University is to develop competent professionals with a Christian worldview for Christian, public, and private schools. To be consistent with the mission, classroom experience in both Christian and public schools should be required for each teacher candidate who successfully completes Liberty’s program. One of the challenges in the implementation of the mission has been an inadequate number of field experience placements available in Christian school settings
Enhancing Christian School Field Experiences through Academic Coaching in a Service-learning Partnership
This article gives an overview of service learning as it relates to learning and understanding a college student’s field of study. A survey was given to our education candidates who were completing a service learning project in a local Christian school. Results from the survey indicate that students were more likely to work in Christian school after having been exposed to this experience
Reflection of Teacher Candidates on Differentiation in the Classroom Using Learning Style Profiles
Remarks on the renormalization of primordial cosmological perturbations
We briefly review the need to perform renormalization of inflationary
perturbations to properly work out the physical power spectra. We also
summarize the basis of (momentum-space) renormalization in curved spacetime and
address several misconceptions found in recent literature on this subject.Comment: 5 page
Relation Between Einstein And Quantum Field Equations
We show that there exists a choice of scalar field modes, such that the
evolution of the quantum field in the zero-mass and large-mass limits is
consistent with the Einstein equations for the background geometry. This choice
of modes is also consistent with zero production of these particles and thus
corresponds to a preferred vacuum state preserved by the evolution. In the
zero-mass limit, we find that the quantum field equation implies the Einstein
equation for the scale factor of a radiation-dominated universe; in the
large-mass case, it implies the corresponding Einstein equation for a
matter-dominated universe. Conversely, if the classical radiation-dominated or
matter-dominated Einstein equations hold, there is no production of scalar
particles in the zero and large mass limits, respectively. The suppression of
particle production in the large mass limit is over and above the expected
suppression at large mass. Our results hold for a certain class of conformally
ultrastatic background geometries and therefore generalize previous results by
one of us for spatially flat Robertson-Walker background geometries. In these
geometries, we find that the temporal part of the graviton equations reduces to
the temporal equation for a massless minimally coupled scalar field, and
therefore the results for massless particle production hold also for gravitons.
Within the class of modes we study, we also find that the requirement of zero
production of massless scalar particles is not consistent with a non-zero
cosmological constant. Possible implications are discussed.Comment: Latex, 24 pages. Minor changes in text from original versio
Revising the observable consequences of slow-roll inflation
We study the generation of primordial perturbations in a (single-field)
slow-roll inflationary universe. In momentum space, these (Gaussian)
perturbations are characterized by a zero mean and a non-zero variance
. However, in position space the variance diverges in the
ultraviolet. The requirement of a finite variance in position space forces one
to regularize . This can (and should) be achieved by proper
renormalization in an expanding universe in a unique way. This affects the
predicted scalar and tensorial power spectra (evaluated when the modes acquire
classical properties) for wavelengths that today are at observable scales. As a
consequence, the imprint of slow-roll inflation on the CMB anisotropies is
significantly altered. We find a non-trivial change in the consistency
condition that relates the tensor-to-scalar ratio to the spectral indices.
For instance, an exact scale-invariant tensorial power spectrum, , is
now compatible with a non-zero ratio , which is forbidden
by the standard prediction (). The influence of relic gravitational
waves on the CMB may soon come within the range of planned measurements,
offering a non-trivial test of the new predictions.Comment: 24 page
Magnetic Flux Expulsion in the Powerful Superbubble Explosions and the Alpha-Omega Dynamo
The possibility of the magnetic flux expulsion from the Galaxy in the
superbubble (SB) explosions, important for the Alpha-Omega dynamo, is
considered. Special emphasis is put on the investigation of the downsliding of
the matter from the top of the shell formed by the SB explosion which is able
to influence the kinematics of the shell. It is shown that either Galactic
gravity or the development of the Rayleigh-Taylor instabilities in the shell
limit the SB expansion, thus, making impossible magnetic flux expulsion. The
effect of the cosmic rays in the shell on the sliding is considered and it is
shown that it is negligible compared to Galactic gravity. Thus, the question of
possible mechanism of flux expulsion in the Alpha-Omega dynamo remains open.Comment: MNRAS, in press, 11 pages, 9 figure
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