How Future Space-Based Weak Lensing Surveys Might Obtain Photometric Redshifts Independently

We study how the addition of on-board optical photometric bands to future space-based weak lensing instruments could affect the photometric redshift estimation of galaxies, and hence improve estimations of the dark energy parameters through weak lensing. Basing our study on the current proposed Euclid configuration and using a mock catalog of galaxy observations, various on-board options are tested and compared with the use of ground-based observations from the Large Synoptic Survey Telescope (LSST) and Pan-STARRS. Comparisons are made through the use of the dark energy Figure of Merit, which provides a quantifiable measure of the change in the quality of the scientific results that can be obtained in each scenario. Effects of systematic offsets between LSST and Euclid photometric calibration are also studied. We find that adding two (U and G) or even one (U) on-board optical band-passes to the space-based infrared instrument greatly improves its photometric redshift performance, bringing it close to the level that would be achieved by combining observations from both space-based and ground-based surveys while freeing the space mission from reliance on external datasets.Comment: Accepted for publication in PASP. A high-quality version of Fig 1 can be found on http://www.ap.smu.ca/~sawicki/DEphoto

Comparative Systematics of Subterranean Amphipod Crustaceans (Hadzioidea)

The research project presented in this doctoral dissertation is a compilation of six published papers. Therefore, instead of being a single comprehensive project, it is composed of a number of sub-projects. Introductory and summary sections provide structure for the compilation of papers. The research for this dissertation investigates the systematics of genera within the amphipod families Hadziidae Karaman, 1943 and Melitidae Bousfield, 1973. In the family Hadziidae, Bahadzia patilarga is described from an anchialine cave on the southern coast of Cuba, B. caymanensis is described from a weakly brackish-water pool in a small cave on Grand Cayman Island in the Cayman Islands, B. yagerae is thoroughly redescribed, and a phylogenetic analysis of Bahadzia and a number of outgroup genera is performed. Two new genera, Paraholsingerius and Tamaweckelia and two new species, P. mexicanus and T. apalpa are desribed from caves in eastern Coahuila and southern Tamaulipas, Mexico respectively. Holsingerius smaragdinus previously known from a single cave in Val Verde Co., Texas, is elevated to the new genus Paraholsingerius and a second population of P. smaragdinus is recorded from northern Coahuila, Mexico. A new record for Paramexiweckelia from a cave in north-central Coahuila is documented. Four new stygobitic species of Hadzia are described from subterranean waters in the Philippines, Palau and Guam. Liagoceradocus is synonymized with Hadziaand an updated diagnosis for the latter is provided. In the family Melitidae three new species of Tegano are described, two from Panglao Island, Bohol, Philippines and one from Peleliu Island, Palau. Tegano is synonymized with Sriha. A new species of Melita is described that has characters intermediate between those used to define the genera Abludomelita, Melitaand Paraniphargus. Based on this new species and studies by previous authors, it is suggested that Abludomelita may need to be synonymized with Melita. The genus Paraniphargus is synonymized with Melita. Flagitopisa philippensis is redescribed based on collections made from various localities throughout the Philippines. Paratypes of Psammogammarus fluviatilisalso from the Philippines were examined and in both this species and F. philippensis, a new structure was described, which consists of a weakly stalked, subovate coxal-like gill attached to the ventral surface of the first pleonite, just anterior to pleopod 1. Based on this unique character, P. fluviatilis is reassignedFlagitopisa

Interval identification of FMR parameters for spin reorientation transition in (Ga,Mn)As

In this work we report results of ferromagnetic resonance studies of a 6% 15 nm (Ga,Mn)As layer, deposited on (001)-oriented GaAs. The measurements were performed with in-plane oriented magnetic field, in the temperature range between 5K and 120K. We observe a temperature induced reorientation of the effective in-plane easy axis from [-110] to [110] direction close to the Curie temperature. The behavior of magnetization is described by anisotropy fields, H_{eff} (= 4\piM -H_{2\perp}), H_{2\parallel}, and H_{4\parallel}. In order to precisely investigate this reorientation, numerical values of anisotropy fields have been determined using powerful - but still largely unknown - interval calculations. In simulation mode this approach makes possible to find all the resonance fields for arbitrarily oriented sample, which is generally intractable analytically. In 'fitting' mode we effectively utilize full experimental information, not only those measurements performed in special, distinguished directions, to reliably estimate the values of important physical parameters as well as their uncertainties and correlations.Comment: 3 pages, 3 figures. Presented at The European Conference "Physics of Magnetism 2011" (PM'11), June 27 - July 1, 2011, Poznan, Polan

Using a Fermionic Ensemble of Systems to Determine Excited States

We discuss a new numerical method for the determination of excited states of a quantum system using a generalization of the Feynman-Kac formula. The method relies on introducing an ensemble of non-interacting identical systems with a fermionic statistics imposed on the systems as a whole, and on determining the ground state of this fermionic ensemble by taking the large time limit of the Euclidean kernel. Due to the exclusion principle, the ground state of an $n$-system ensemble is realized by the set of individual systems occupying successively the $n$ lowest states, all of which can therefore be sampled in this way. To demonstrate how the method works, we consider a one-dimensional oscillator and a chain of harmonically coupled particles.Comment: 14 pages, Latex + 4 eps figure

Are Scattering Properties of Graphs Uniquely Connected to Their Shapes?

The famous question of Mark Kac "Can one hear the shape of a drum?" addressing the unique connection between the shape of a planar region and the spectrum of the corresponding Laplace operator can be legitimately extended to scattering systems. In the modified version one asks whether the geometry of a vibrating system can be determined by scattering experiments. We present the first experimental approach to this problem in the case of microwave graphs (networks) simulating quantum graphs. Our experimental results strongly indicate a negative answer. To demonstrate this we consider scattering from a pair of isospectral microwave networks consisting of vertices connected by microwave coaxial cables and extended to scattering systems by connecting leads to infinity to form isoscattering networks. We show that the amplitudes and phases of the determinants of the scattering matrices of such networks are the same within the experimental uncertainties. Furthermore, we demonstrate that the scattering matrices of the networks are conjugated by the, so called, transplantation relation.Comment: 3 figures; Physical Review Letters, 201

Genetic analysis of non-recessive factors of resistance to diazinon in the SKA strain of the housefly (Musca domestica L)

RESP-560

New Species of Amphipod Crustaceans in the Genera Tegano and Melita (Hadzioidea : Melitidae) From Subterranean Groundwaters in Guam, Palau, and the Philippines

Three new species of Tegano are described, two from caves on Panglao Island, Bohol, Philippines, and one from a cave on Peleliu Island, Palau. Sriha vagabunda from Sri Lanka is reassigned to the genus Tegano based primarily on the high degree of similarity between Sriha vagabunda and species of Tegano and the fact that these species exhibit a great deal of variation in the reduction of the mandibular palp. A new species of Melita with characters intermediate between those defining the genera Abludomelita, Melita, and Paraniphargus is described from a spring on Guam. The characters of the new species and studies by previous authors suggest that Abludomelita may not be as distinct from Melita as previously believed. The troglomorphic genus Paraniphargus from the Andaman Islands and Java is reevaluated and synonymized with Melita

Rick Sawicki Interview for Dartmouth Engineer Magazine

In this issue Rick Sawicki answers the question--What is your role as chief engineer on this project? His reply is--There are two major roles for the Chief Engineer position: (1) to assure that the engineering that is being performed for the project is safely completed in full compliance with all federal, state and Lawrence Livermore National Laboratory policies, standards and procedures and (2) as needed, address special engineering issues as they arise assuring that their resolution is completed in the safest, most effective manner consistent with the project's budget and schedule constraints. Currently the project is nearing completion. Many activities are rapidly coming to a conclusion and many new, complex systems are being activated. I am presently playing a major role in coordinating these activities so that the work can be executed safely and efficiently and the project will complete on schedule. He also answers the following questions: (1) What is the timetable to have this facility up and running for experimentation; (2) Where is the facility; (3) How large is your team of designers, engineers, etc.; (4) What are the means of achieving nuclear fusion; (5) What are the special engineering challenges of this project; (6) How close are scientists to achieving nuclear fusion; (7) What safety issues are involved in nuclear fusion; (8) Are there any waste issues involved in nuclear fusion that need to be solved; (9) Are there security issues to take into consideration in designing a facility for nuclear fusion; (10) Do you work directly with any of the scientists who are working on nuclear fusion; (11) What are kinds of engineers are needed in your area of expertise; and (12) Anything else you think is important for people to know about nuclear fusion as a piece of the energy solutions puzzle