1,420 research outputs found
On the supersymmetric vacua of the Veneziano-Wosiek model
We study the supersymmetric vacua of the Veneziano-Wosiek model in sectors
with fermion number F=2, 4 at finite 't Hooft coupling lambda. We prove that
for F=2 there are two zero energy vacua for lambda > lambda_c = 1 and none
otherwise. We give the analytical expressions of both vacua. One of them was
previously known, the second one is obtained by solving the cohomology of the
supersymmetric charges. At F=4 we compute the would-be supersymmetric vacua at
high order in the the strong coupling expansion and provide strong support to
the conclusion that lambda = 1 is a critical point in this sector too. It
separates a strong coupling phase with two symmetric vacua from a weak coupling
phase with positive spectrum.Comment: 17 pages, 2 eps figure
Recommended from our members
Atmospheric black carbon and warming effects influenced by the source and absorption enhancement in central Europe
Particles containing black carbon (BC), a strong absorbing substance, exert a rather uncertain direct and indirect radiative forcing in the atmosphere. To investigate the mass concentration and absorption properties of BC particles over central Europe, the model WRF-Chem was used at a resolution of 12 km in conjunction with a high-resolution BC emission inventory (EUCAARI 42-Pan-European Carbonaceous Aerosol Inventory; 1/8° Ă 1/16°). The model simulation was evaluated using measurements of equivalent soot carbon, absorption coefficients and particle number concentrations at seven sites within the German Ultrafine Aerosol Network, PM mass concentrations from the dense measurement network of the German Federal Environmental Agency at 392 monitoring stations, and aerosol optical depth from MODIS and AERONET. A distinct time period (25 March to 10 April 2009) was chosen, during which the clean marine air mass prevailed in the first week and afterwards the polluted continental air mass mainly from the southeast dominated with elevated daily average BC concentration of up to 4 ÎŒ g mâ3. The simulated PM mass concentration, aerosol number concentration and optical depth were in good agreement with the observations, while the modelled BC mass concentrations were found to be a factor of 2 lower than the observations. Together with back trajectories, detailed model bias analyses suggested that the current BC emission in countries to the east and south of Germany might be underestimated by a factor of 5, at least for the simulation period. Running the model with upscaled BC emissions in these regions led to a smaller model bias and a better correlation between model and measurement. In contrast, the particle absorption coefficient was positively biased by about 20% even when the BC mass concentration was underestimated by around 50%. This indicates that the internal mixture treatment of BC in the WRF-Chem optical calculation is unrealistic in our case, which overamplifies the light absorption by BC-containing particles. By adjusting the modelled mass absorption cross-section towards the measured values, the simulation of particle light absorption of BC was improved as well. Finally, the positive direct radiative forcing of BC particles at the top of the atmosphere was estimated to be in the range of 0 to +4 W mâ2 over Germany for the model run with improved BC mass concentration and adjusted BC light absorption cross-section. This adjustment lowered the positive forcing of BC by up to 70%, compared with the internal mixing treatment of BC in the model simulation
Recognizing basal cell carcinoma on smartphoneâcaptured digital histopathology images with a deep neural network
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154530/1/bjd18026.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154530/2/bjd18026_am.pd
A note on Friedmann equation of FRW universe in deformed Horava-Lifshitz gravity from entropic force
With entropic interpretation of gravity proposed by Verlinde, we obtain the
Friedmann equation of the Friedmann-Robertson-Walker universe for the deformed
Ho\v{r}ava-Lifshitz gravity. It is shown that, when the parameter of
Ho\v{r}ava-Lifshitz gravity , the modified Friedmann
equation will go back to the one in Einstein gravity. This results may imply
that the entropic interpretation of gravity is effective for the deformed
Ho\v{r}ava-Lifshitz gravity.Comment: 9 pages, no figure
Pyramid multi-loss vision transformer for thyroid cancer classification using cytological smear
Multi-instance learning, a commonly used technique in artificial intelligence for analyzing slides, can be applied to diagnose thyroid cancer based on cytological smears. Since smears do not have mul-tidimensional histological features similar to histopathology, mining potential contextual information and diversity of features is crucial for better classification performance. In this paper, we propose a pyramid multi-loss vision transformer model called PyMLViT, a novel algorithm with two core modules to address these issues. Specifically, we design a pyramid token extraction module to acquire potential contextual information on smears. The pyramid token structure extracts multi-scale local features, and the vision transformer structure further obtains global information through the self -attention mechanism. Furthermore, we construct multi-loss fusion module based on the conventional multi-instance learning framework. With carefully designed bag and patch weight allocation strategies, we incorporate slide-level annotations as pseudo-labels for patches to participate in training, thus enhancing the diversity of supervised information. Extensive experimental results on the real-world dataset show that PyMLViT has a high performance and a competitive number of parameters compared to popular methods for diagnosing thyroid cancer in cytological smears.& COPY; 2023 Elsevier B.V. All rights reserved.Radiolog
Bedoi: Benchmarks For Determining Overlapping Images With Photogrammetric Information
For conventional SfM pipeline, image matching is enduring limitation when considering the time efficiency. In the last few years, to speed up image matching procedure, many image retrieval works were proposed to fast find overlapping image pairs, e.g., bag-of-word that clusters hand-crafted local features in a hierarchical way for efficient similar image retrieval, or learning-based global features (such as, VGG or ResNet) are used to represent image in a global compact manner. However, there are rarely benchmarks with referenced overlapping information to: first, evaluate the retrieval performance; second, fine tune deep-learning models along the direction that is more capable to deal with overlapping image pairs. In this work, based on traditional photogrammetric procedures, relevant photogrammetric information is obtained including image orientation parameters, 3D mesh model and etc., we then generate a benchmark for determining Overlapping Images - BeDOI, in which referenced pairwise overlapping relationships are estimated via rigorous photogrammetric geometry. To extend the generality, in total, BeDOI contains 13667 images which are basically UAV and close-range images of various scene categories, e.g., urban cities, campus, village, historical relics, green land, buildings and etc. Lastly, to demonstrate the efficacy of the proposed BeDOI, several image retrieval methods are tested and the experimental results are reported as a competition challenge
Electrical transport studies of quench condensed Bi films at the initial stage of film growth: Structural transition and the possible formation of electron droplets
The electrical transport properties of amorphous Bi films prepared by
sequential quench deposition have been studied in situ. A
superconductor-insulator (S-I) transition was observed as the film was made
increasingly thicker, consistent with previous studies. Unexpected behavior was
found at the initial stage of film growth, a regime not explored in detail
prior to the present work. As the temperature was lowered, a positive
temperature coefficient of resistance (dR/dT > 0) emerged, with the resistance
reaching a minimum before the dR/dT became negative again. This behavior was
accompanied by a non-linear and asymmetric I-V characteristic. As the film
became thicker, conventional variable-range hopping (VRH) was recovered. We
attribute the observed crossover in the electrical transport properties to an
amorphous to granular structural transition. The positive dR/dT found in the
amorphous phase of Bi formed at the initial stage of film growth was
qualitatively explained by the formation of metallic droplets within the
electron glass.Comment: 7 pages, 6 figure
Measurements of the observed cross sections for exclusive light hadrons containing at , 3.650 and 3.6648 GeV
By analyzing the data sets of 17.3, 6.5 and 1.0 pb taken,
respectively, at , 3.650 and 3.6648 GeV with the BES-II
detector at the BEPC collider, we measure the observed cross sections for
, , ,
and at the three energy
points. Based on these cross sections we set the upper limits on the observed
cross sections and the branching fractions for decay into these
final states at 90% C.L..Comment: 7 pages, 2 figure
Partial wave analysis of J/\psi \to \gamma \phi \phi
Using events collected in the BESII detector, the
radiative decay is
studied. The invariant mass distribution exhibits a near-threshold
enhancement that peaks around 2.24 GeV/.
A partial wave analysis shows that the structure is dominated by a
state () with a mass of
GeV/ and a width of GeV/. The
product branching fraction is: .Comment: 11 pages, 4 figures. corrected proof for journa
- âŠ