1,713 research outputs found
Thermodynamic limits to information harvesting by sensory systems
In view of the relation between information and thermodynamics we investigate
how much information about an external protocol can be stored in the memory of
a stochastic measurement device given an energy budget. We consider a layered
device with a memory component storing information about the external
environment by monitoring the history of a sensory part coupled to the
environment. We derive an integral fluctuation theorem for the entropy
production and a measure of the information accumulated in the memory device.
Its most immediate consequence is that the amount of information is bounded by
the average thermodynamic entropy produced by the process. At equilibrium no
entropy is produced and therefore the memory device does not add any
information about the environment to the sensory component. Consequently, if
the system operates at equilibrium the addition of a memory component is
superfluous. Such device can be used to model the sensing process of a cell
measuring the external concentration of a chemical compound and encoding the
measurement in the amount of phosphorylated cytoplasmic proteins.Comment: Revised version: 18 pages, 5 figure
Gravity Effects on Neutrino Masses in Split Supersymmetry
The mass differences and mixing angles of neutrinos can neither be explained
by R-Parity violating split supersymmetry nor by flavor blind quantum gravity
alone. It is shown that combining both effects leads, within the allowed
parameter range, to good agreement with the experimental results. The
atmospheric mass is generated by supersymmetry through mixing between neutrinos
and neutralinos, while the solar mass is generated by gravity through flavor
blind dimension five operators. Maximal atmospheric mixing forces the tangent
squared of the solar angle to be equal to 1/2. The scale of the quantum gravity
operator is predicted within a 5% error, implying that the reduced Planck scale
should lie around the GUT scale. In this way, the model is very predictive and
can be tested at future experiments.Comment: 12 pages, 9 figures; In section 3 we extend our discussion about the
definition of flavor basis in order to clarify in which basis the Gravity
contributions are flavor blind. In the section 4 we add some words to explain
why the Gravity contributions will not affect the charged lepton mass matrix;
Finally we also fixed some minor typos regarding units or plot label
Neutrino Masses in Split Supersymmetry
We investigate the possibility to generate neutrino masses in the context of
Split supersymmetric scenarios where all sfermions are very heavy. All relevant
contributions coming from the R-parity violating terms to the neutrino mass
matrix up to one-loop level are computed, showing the importance of the Higgs
one-loop corrections. We conclude that it is not possible to generate all
neutrino masses and mixings in Split SUSY with bilinear R-Parity violating
interactions. In the case of Partial Split SUSY the one-loop Higgs
contributions are enough to generate the neutrino masses and mixings in
agreement with the experiment. In the context of minimal SUSY SU(5) we find new
contributions which help us to generate neutrino masses in the case of Split
SUSY.Comment: 33 pages, 6 figures, to appear in Physical Review
Will we observe black holes at LHC?
The generalized uncertainty principle, motivated by string theory and
non-commutative quantum mechanics, suggests significant modifications to the
Hawking temperature and evaporation process of black holes. For
extra-dimensional gravity with Planck scale O(TeV), this leads to important
changes in the formation and detection of black holes at the the Large Hadron
Collider. The number of particles produced in Hawking evaporation decreases
substantially. The evaporation ends when the black hole mass is Planck scale,
leaving a remnant and a consequent missing energy of order TeV. Furthermore,
the minimum energy for black hole formation in collisions is increased, and
could even be increased to such an extent that no black holes are formed at LHC
energies.Comment: 5 pages, 2 figures. Minor changes to match version to appear in
Class. Quant. Gra
The Inflatino Problem in Supergravity Inflationary Models
We consider the potential problems due to the production of inflatinos and
gravitinos after inflation. Inflationary models with a single scale set by the
microwave background anisotropies have a low enough reheat temperature to avoid
problems with the thermal production of gravitinos. Moreover, the nonthermal
production of gravitinos has been shown to be sufficiently small if the sector
ultimately responsible for supersymmetry breaking is coupled only
gravitationally to the inflationary sector. Still, in some models, inflatinos
can be created during preheating with a substantial abundance. The main
contribution to the gravitino abundance may thus come from their decay into the
inflaton, or into its scalar partner, as well as from the inverse processes. We
show that this production needs to be strongly suppressed. This suppression can
be realized in the simplest scenarios which typically have a sufficiently high
inflationary scale.Comment: 18 page
Uncertainties in limits on TeV-gravity from neutrino-induced showers
In models with TeV-scale gravity, ultrahigh energy cosmic rays can generate
microscopic black holes in the collision with atmospheric and terrestrial
nuclei. It has been proposed that stringent bounds on TeV-scale gravity can be
obtained from the absence of neutrino cosmic ray showers mediated by black
holes. However, uncertainties in the cross section of black hole formation and,
most importantly, large uncertainties in the neutrino flux affects these
bounds. As long as the cosmic neutrino flux remains unknown, the
non-observation of neutrino induced showers implies less stringent limits than
present collider limits.Comment: Changes to match published versio
Cognitive Gadgets: A provocative but flawed manifesto.
The argument against innatism at the heart of Cognitive Gadgets is provocative but premature, and is vitiated by dichotomous thinking, interpretive double standards, and evidence cherry-picking. I illustrate my criticism by addressing the heritability of imitation and mindreading, the relevance of twin studies, and the meaning of cross-cultural differences in theory of mind development. Reaching an integrative understanding of genetic inheritance, plasticity, and learning is a formidable task that demands a more nuanced evolutionary approach
Children’s work as a window into the energetic, reproductive, and cognitive trade-offs of human life history: A comment on Lancy.
Rethinking the fast-slow continuum of individual differences
The idea that individual differences in behavior and physiology can be partly understood by linking them to a fast-slow continuum of life history strategies has become popular in the evolutionary behavioral sciences. I refer to this approach as the “fast-slow paradigm” of individual differences. The paradigm has generated a substantial amount of research, but has also come increasingly under scrutiny for theoretical, empirical, and methodological reasons. I start by reviewing the basic empirical facts about the fast-slow continuum across species and the main theoretical accounts of its existence. I then discuss the move from the level of species and populations to that of individuals, and the theoretical and empirical complications that follow. I argue that the fast-slow continuum can be a productive heuristic for individual differences; however, the field needs to update its theoretical assumptions, rethink some methodological practices, and explore new approaches and ideas in light of the specific features of the human ecology
- …
