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Institution

California Institute of Technology

EducationPasadena, California, United States
About: California Institute of Technology is a education organization based out in Pasadena, California, United States. It is known for research contribution in the topics: Galaxy & Population. The organization has 57649 authors who have published 146691 publications receiving 8620287 citations. The organization is also known as: Caltech & Cal Tech.


Papers
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Book ChapterDOI
TL;DR: In this article, the authors conducted experiments in Vietnamese villages to determine the predictors of risk and time preferences and found that people are less loss-averse and more patient in villages with higher mean income.
Abstract: We conducted experiments in Vietnamese villages to determine the predictors of risk and time preferences. In villages with higher mean income, people are less loss-averse and more patient. Household income is correlated with patience but not with risk. We expand measurements of risk and time preferences beyond expected utility and exponential discounting, replacing those models with prospect theory and a three-parameter hyperbolic discounting model. Comparable risk parameter estimates have been found for Chinese farmers, using our method.

930 citations

Journal ArticleDOI
TL;DR: P polarization-insensitive, micron-thick, high-contrast transmitarray micro-lenses with focal spots as small as 0.57 λ are reported, thus enabling widespread adoption and a rigorous method for ultrathin lens design is discussed.
Abstract: Flat optical devices thinner than a wavelength promise to replace conventional free-space components for wavefront and polarization control. Transmissive flat lenses are particularly interesting for applications in imaging and on-chip optoelectronic integration. Several designs based on plasmonic metasurfaces, high-contrast transmitarrays and gratings have been recently implemented but have not provided a performance comparable to conventional curved lenses. Here we report polarization-insensitive, micron-thick, high-contrast transmitarray micro-lenses with focal spots as small as 0.57 λ. The measured focusing efficiency is up to 82%. A rigorous method for ultrathin lens design, and the trade-off between high efficiency and small spot size (or large numerical aperture) are discussed. The micro-lenses, composed of silicon nano-posts on glass, are fabricated in one lithographic step that could be performed with high-throughput photo or nanoimprint lithography, thus enabling widespread adoption.

930 citations

Journal ArticleDOI
03 Jul 2009-Science
TL;DR: Results suggest that the soil at the Phoenix landing site must have suffered alteration through the action of liquid water in geologically the recent past, and revealed an alkaline environment in contrast to that found by the Mars Exploration Rovers, indicating that many different environments have existed on Mars.
Abstract: The Wet Chemistry Laboratory on the Phoenix Mars Lander performed aqueous chemical analyses of martian soil from the polygon-patterned northern plains of the Vastitas Borealis. The solutions contained ~10 mM of dissolved salts with 0.4 to 0.6% perchlorate (ClO 4 ) by mass leached from each sample. The remaining anions included small concentrations of chloride, bicarbonate, and possibly sulfate. Cations were dominated by Mg 2+ and Na + , with small contributions from K + and Ca 2+ . A moderately alkaline pH of 7.7 ± 0.5 was measured, consistent with a carbonate-buffered solution. Samples analyzed from the surface and the excavated boundary of the ~5-centimeter-deep ice table showed no significant difference in soluble chemistry.

929 citations

Journal ArticleDOI
TL;DR: In this article, a topological superconducting phase supporting Majorana fermions can be realized using surprisingly conventional building blocks: a semiconductor quantum well coupled to an s-wave superconductor and a ferromagnetic insulator.
Abstract: The experimental realization of Majorana fermions presents an important problem due to their non-Abelian nature and potential exploitation for topological quantum computation. Very recently Sau et al. [Phys. Rev. Lett. 104, 040502 (2010)] demonstrated that a topological superconducting phase supporting Majorana fermions can be realized using surprisingly conventional building blocks: a semiconductor quantum well coupled to an s-wave superconductor and a ferromagnetic insulator. Here we propose an alternative setup, wherein a topological superconducting phase is driven by applying an in-plane magnetic field to a (110)-grown semiconductor coupled only to an s-wave superconductor. This device offers a number of advantages, notably a simpler architecture and the ability to tune across a quantum phase transition into the topological superconducting state while still largely avoiding unwanted orbital effects. Experimental feasibility of both setups is discussed in some detail.

929 citations

Journal ArticleDOI
TL;DR: It is demonstrated with a change blindness data set that the distance between images induced by the image signature is closer to human perceptual distance than can be achieved using other saliency algorithms, pixel-wise, or GIST descriptor methods.
Abstract: We introduce a simple image descriptor referred to as the image signature. We show, within the theoretical framework of sparse signal mixing, that this quantity spatially approximates the foreground of an image. We experimentally investigate whether this approximate foreground overlaps with visually conspicuous image locations by developing a saliency algorithm based on the image signature. This saliency algorithm predicts human fixation points best among competitors on the Bruce and Tsotsos [1] benchmark data set and does so in much shorter running time. In a related experiment, we demonstrate with a change blindness data set that the distance between images induced by the image signature is closer to human perceptual distance than can be achieved using other saliency algorithms, pixel-wise, or GIST [2] descriptor methods.

929 citations


Authors

Showing all 58155 results

NameH-indexPapersCitations
Eric S. Lander301826525976
Donald P. Schneider2421622263641
George M. Whitesides2401739269833
Yi Chen2174342293080
David Baltimore203876162955
Edward Witten202602204199
George Efstathiou187637156228
Michael A. Strauss1851688208506
Jing Wang1844046202769
Ruedi Aebersold182879141881
Douglas Scott1781111185229
Hyun-Chul Kim1764076183227
Phillip A. Sharp172614117126
Timothy M. Heckman170754141237
Zhenan Bao169865106571
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
2023176
2022737
20214,682
20205,519
20195,321
20185,133