Earth & Environmental Sciences, Rast-Holbrook Seminar
Date:
-
Location:
303 Slone Research Building
Event Series:
Astro Seminar: Star Formation and Stellar Populations of Ultra-Luminous Galaxies at High Redshifts
The Herschel space mission has generated, for the first time, a rich data set
that allow us to explore the far-IR (FIR) universe at z > 1 on a large scale
that is comparable to those in optical/near-IR. As the mission is now over,
these are the best -- and all -- that we can have before the next generation FIR
facilities arrive. We are undertaking a program to study the extreme,
dust-enshrouded star formation in galaxies at z >1, targeting the
Ultra-Luminous InfraRed Galaxies (ULIRGs) revealed by the Herschel very
wide-field surveys. The most serious challenge is the persisting problem of
poor angular resolution in FIR/sub-mm that the Herschel still suffered. We are
developing a method to extract the major component(s) of Herschel sources using
optical data directly as the position priors, which is appropriate to the
study of ULIRGs. We will construct the largest, well-defined sample of high-z
ULIRG, whose total IR luminosity are directly measured based on multiple FIR
bands, and to enable a slew of follow-up studies. Some preliminary results will
be presented here.
Date:
-
Location:
CP179
Condensed Matter Seminar: Inversion Techniques for Scanning Tunneling Microscopy (STM) Data Analyses
In this first part of the talk, we will discuss two techniques that we term as “Inversion” techniques : a technique that extracts information regarding the Hamiltonian/physics of the sample from the STM data with minimal assumptions (e.g. existence of well-defined quasiparticles). Both techniques are based on quasiparticle interference. The first technique can be used to locate the scattering impurities by analyzing the oscillations in energy of STM spectra due to nearby scatterers. In the case of a superconductor, the method can potentially distinguish the nature of the scattering by a particular impurity. The second technique gives a method to extract the lifetime of a quasiparticle by using the STM data around an impurity.
In the second part of the talk, we deal with a specific part of STM phenomenology of the high temperature superconductor, $Bi_2 Sr_2 Ca_1 Cu_2 O_{8+x}$. It concerns the high-energy features outside the gap seen in the STM experiments on BSCCO. Jinho Lee et al (Nature 442, 546 (2006)) showed that these features were a result of a bosonic mode’s coupling to the
electrons in the CuO2 layer. Using a simplified model of d-wave BCS quasiparticles weakly coupled to Einstein oscillators, we give an answer to : a) how to extract the frequency of the bosonic mode, and b) how to extract an estimate of the electron-boson coupling strength. We confirm a posteriori the validity of our weak coupling assumption.
Date:
-
Location:
CP179
Theory Seminar: Hadron electric polarizability from Lattice QCD
Electromagnetic polarizabilities are important parameters for understanding the interaction between photons and hadrons. For most hadrons these quantities are poorly constrained experimentally since they can only be measured indirectly. New experiments at CERN and Jefferson Lab are planned that will measure the polarizabilities more precisely. Lattice QCD can be used to compute these quantities directly in terms of quark and gluons degrees of freedom, using the background field method. We present results for the electric polarizability for two different quark masses, light enough to connect to chiral perturbation theory. These are currently the lightest quark masses used in polarizability studies. For each pion mass we compute the polarizability at four different volumes and perform an infinite volume extrapolation. For one ensemble, we also discuss the effect of turning on the coupling between the background field and the sea quarks.
Date:
-
Location:
CP179
Archaeology Roundtable: Anthropology Undergraduate Student Presentations
Date:
-
Location:
Lafferty Hall Rm. 108
Event Series:
Ohio River Analysis Meeting
The Ohio River Analysis Meeting is a collaborative activity sponsored by the University of Kentucky and the University of Cincinnati. The fifth edition of the meeting will take place in Cincinnati on 28 February and 1 March 2015. Please see the website http://math.uc.edu/ORAM/ORAM5/ for more information.
Date:
-
Location:
University of Cincinnati
Achilles & the Argonauts: CLA 525/625 Research Workshop
Research workshop on the unfinished Flavian Epics, Valerius Flaccus' Argonautica and Statius' Achilleid presented by students enrolled in CLA 525/625. There will be coffee breaks, lunch and a reception, followed by dinner with our Keynote Speaker.
Date:
-
Location:
Alumni Gallery in the Young Library
Event Series:
