8,032 research outputs found
Nonequilibrium functional renormalization group for interacting quantum systems
We propose a nonequilibrium version of functional renormalization within the
Keldysh formalism by introducing a complex valued flow parameter in the Fermi
or Bose functions of each reservoir. Our cutoff scheme provides a unified
approach to equilibrium and nonequilibrium situations. We apply it to
nonequilibrium transport through an interacting quantum wire coupled to two
reservoirs and show that the nonequilibrium occupation induces new power law
exponents for the conductance.Comment: 5 pages, 2 figures; published versio
Are Noachian-age ridged plains (Nplr) actually early Hesperian in age
Whether or not the Nplr units in Memnonia and Argyre truly represent ridged plains volcanism of Noachian age or are simply areas of younger (Early Hesperian age) volcanism which failed to bury older craters and therefore have a greater total crater age than really applies to the ridged plains portion of those terrains is examined. The Nuekum and Hiller technique is used to determine the number of preserved crater retention surfaces in the Memnonia and Argyre regions where Scott and Tanaka show Nplr units to be common. The results for cratered terrain (Npl) in Memnonia is summarized along with those for ridged plains (Nplr) in both Memnonia and Argyre, and they are compared with similar results obtained for Tempe Terra and Lunae Plunum
Report of the University of Missouri-Orissa University of Agriculture technology study team
Cover title.Includes bibliographical references (pages 34-36)
Improving the Inventory of Large Lunar Basins: Using Lola Data to Test Previous Candidates and Search for New Ones
Topography and crustal thickness data from LOLA altimetry were used to test the validity of 98 candidate large lunar basins derived from photogeologic and earlier topographic and crustal thickness data, and to search for possible new candidates. We eliminate 23 previous candidates but find good evidence for 20 new candidates. The number of basins > 300 km diameter on the Moon is almost certainly a factor 2 (maybe 3?) larger than the number of named features having basin-like topography
The One-dimensional KPZ Equation and the Airy Process
Our previous work on the one-dimensional KPZ equation with sharp wedge
initial data is extended to the case of the joint height statistics at n
spatial points for some common fixed time. Assuming a particular factorization,
we compute an n-point generating function and write it in terms of a Fredholm
determinant. For long times the generating function converges to a limit, which
is established to be equivalent to the standard expression of the n-point
distribution of the Airy process.Comment: 15 page
Retinal Vessel Segmentation Using the 2-D Morlet Wavelet and Supervised Classification
We present a method for automated segmentation of the vasculature in retinal
images. The method produces segmentations by classifying each image pixel as
vessel or non-vessel, based on the pixel's feature vector. Feature vectors are
composed of the pixel's intensity and continuous two-dimensional Morlet wavelet
transform responses taken at multiple scales. The Morlet wavelet is capable of
tuning to specific frequencies, thus allowing noise filtering and vessel
enhancement in a single step. We use a Bayesian classifier with
class-conditional probability density functions (likelihoods) described as
Gaussian mixtures, yielding a fast classification, while being able to model
complex decision surfaces and compare its performance with the linear minimum
squared error classifier. The probability distributions are estimated based on
a training set of labeled pixels obtained from manual segmentations. The
method's performance is evaluated on publicly available DRIVE and STARE
databases of manually labeled non-mydriatic images. On the DRIVE database, it
achieves an area under the receiver operating characteristic (ROC) curve of
0.9598, being slightly superior than that presented by the method of Staal et
al.Comment: 9 pages, 7 figures and 1 table. Accepted for publication in IEEE
Trans Med Imag; added copyright notic
Kramers degeneracy theorem in nonrelativistic QED
Degeneracy of the eigenvalues of the Pauli-Fierz Hamiltonian with spin 1/2 is
proven by the Kramers degeneracy theorem. The Pauli-Fierz Hamiltonian at fixed
total momentum is also investigated.Comment: LaTex, 11 page
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