36 research outputs found
Idan Ben-Barak: Cook Prize 2024, Silver Medal Acceptance Speech.
No full textAuthor Idan Ben-Barak gives an acceptance speech for We Go Way Back (Roaring Brook Press)https://educate.bankstreet.edu/cook/1010/thumbnail.jp
Photon production from the scattering of axions out of a solenoidal magnetic field
No full textWe calculate the total cross section for the production of photons from the scat- tering of axions by a strong inhomogeneous magnetic field in the form of a 2D δ-function, a cylindrical step function and a 2D Gaussian distribution, which can be approximately pro- duced by a solenoidal current. The theoretical result is used to estimate the axion-photon conversion probability which could be expected in a reasonable experimental situation. Com- parison between the 2D conversion probabilities for QCD inspired axions and those derived by applying the celebrated 1D calculation of the (inverse) coherent Primakoff effect is made using an averaging prescription procedure of the 1D case. We also consider scattering at a resonance Eaxion ∼ maxion, which corresponds to the scattering from a δ-function and gives the most enhanced results. Finally, we analyze the results of this work in the astrophysical extension to suggest a way in which they may be directed to a solution to some basic solar physics problems and, in particular, the coronal heating problem
Axions and Photons In Terms of Particles and Anti-Particles
No full textThe axion photon system in an external magnetic field, when for example considered with the geometry of the experiments exploring axion photon mixing (which can be represented by a 1+1 effective model) displays a continuous axion-photon duality symmetry in the limit the axion mass is neglected. The conservation law that follows from this symmetry is obtained. The magnetic field interaction is seen to be equivalent to first order to the interaction of a complex charged field with an external electric potential, where this ficticious electric potential is proportional to the external magnetic field. This allows one to solve for the scattering amplitudes using already known scalar QED results. Axion photon oscillations can be understood as violations of a charge symmetry in the scalar QED language. Going beyond the linear theory, the axion photon system in a self consistent magnetic field is shown, using this formalism, to have interesting soliton solutions that represent new non gravitational ways of trapping light. Finally, generalizing the scalar QED formalism to 2+1 dimensions makes it clear that a photon and an axion splitt into two components in an inhomogeneous magnetic field, an effect that reminds us of the Stern Gerlach experiment
Urban Permeation
No full textUrban permeation and local integration of socioeconomic relations in Sector 4 & 5 in the municipality of Ecatepec de MorelosDSD - Urban AsymmetriesArchitectur
Confinement-induced accumulation and spontaneous de-mixing of microscopic active-passive mixtures
No full textUnderstanding the out-of-equilibrium properties of noisy microscale systems
and the extent to which they can be modulated externally, is a crucial
scientific and technological challenge. It holds the promise to unlock
disruptive new technologies ranging from targeted delivery of chemicals within
the body to directed assembly of new materials. Here we focus on how active
matter can be harnessed to transport passive microscopic systems in a
statistically predictable way. Using a minimal active-passive system of weakly
Brownian particles and swimming microalgae, we show that spatial confinement
leads to a complex non-monotonic steady-state distribution of colloids, with a
pronounced peak at the boundary. The particles' emergent active dynamics is
well captured by a space-dependent Poisson process resulting from the
space-dependent motion of the algae. Based on our findings, we then realise
experimentally the spontaneous de-mixing of the active-passive suspension,
opening the way for manipulating colloidal objects via controlled activity
fields
Dynamics and Modulation of Synaptic Transmission in the Mammalian CNS
No full textThis eBook is a collection of articles from a Frontiers Research Topic. Frontiers Research Topics are very popular trademarks of the Frontiers Journals Series: they are collections of at least ten articles, all centered on a particular subject. With their unique mix of varied contributions from Original Research to Review Articles, Frontiers Research Topics unify the most influential researchers, the latest key findings and historical advances in a hot research area! Find out more on how to host your own Frontiers Research Topic or contribute to one as an author by contacting the Frontiers Editorial Office: frontiersin.org/about/contac
Computational experiments with medium to large scale parametric quadratic programming problems
No full textThis thesis was scanned from the print manuscript for digital preservation and is copyright the author.
Researchers can access this thesis by asking their local university, institution or public library to
make a request on their behalf. Monash staff and postgraduate students can use the link in the References field
Asset Pricing Implications Of The Mismatch Between Performance Window And Benchmark Duration
No full textShort performance windows shrink fund managers' investment horizons well below
value investors' long-term investment mandates. We unravel that the frictions tied to
the asset management industry are responsible for the recent empirical ndings show-
ing that the risk premium, volatility, and Sharpe ratio on short-term dividend strips
are higher than long-term dividend strips | ndings that are at odds with the lead-
ing equilibrium asset pricing models. The interplay between fund managers' relative
performance objective and short-term performance window is the primary equilibrium
channel, which remains robust to various extensions. Our continuous-time setup admits
closed-form expressions and is supported by additional empirical evidence.https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3852487First author draf
