Commutators of lepton mass matrices associated with seesaw and leptogenesis

The origin of tiny neutrino masses and the baryon number asymmetry of the Universe are naturally interpreted by the canonical seesaw and leptogenesis mechanisms, in which there are the heavy Majorana neutrino mass matrix $M_{\rm R}$, the Dirac neutrino mass matrix $M_{\rm D}$, the charged-lepton mass matrix $M_\ell$ and the effective (light) neutrino mass matrix $M_\nu$. We find that ${\rm Im}\left(\det\left[ M^\dagger_{\rm D} M_{\rm D}, M^\dagger_{\rm R} M_{\rm R} \right]\right)$, ${\rm Im}\left(\det\left[ M_\ell M^\dagger_\ell, M_\nu M^\dagger_\nu \right]\right)$ and ${\rm Im}\left(\det\left[ M_\ell M^\dagger_\ell, M_{\rm D} M^\dagger_{\rm D} \right]\right)$ can serve for a basis-independent measure of CP violation associated with lepton-number-violating decays of heavy neutrinos, flavor oscillations of light neutrinos and lepton-flavor-violating decays of charged leptons, respectively. We first calculate these quantities with the help of a standard parametrization of the $6\times 6$ flavor mixing matrix, and then discuss their implications on both leptogenesis and CP violation at low energy scales. A comparison with the weak-basis invariants of leptogenesis as proposed by Branco {\it et al} is also made.Comment: LaTex 8 pages. Minor changes. Accepted for publication in Phys. Rev.

A Comprehensive Survey on Vector Database: Storage and Retrieval Technique, Challenge

A vector database is used to store high-dimensional data that cannot be characterized by traditional DBMS. Although there are not many articles describing existing or introducing new vector database architectures, the approximate nearest neighbor search problem behind vector databases has been studied for a long time, and considerable related algorithmic articles can be found in the literature. This article attempts to comprehensively review relevant algorithms to provide a general understanding of this booming research area. The basis of our framework categorises these studies by the approach of solving ANNS problem, respectively hash-based, tree-based, graph-based and quantization-based approaches. Then we present an overview of existing challenges for vector databases. Lastly, we sketch how vector databases can be combined with large language models and provide new possibilities

New approach to electroweak symmetry nonrestoration

Electroweak symmetry nonrestoration up to high temperatures well above the electroweak scale offers new alternatives for baryogenesis. We propose a new approach for electroweak symmetry nonrestoration via an inert Higgs sector that couples to the Standard Model Higgs as well as an extended scalar singlet sector. We implement renormalization group improvements and thermal resummation, necessary to evaluate the effective potential spanning over a broad range of energy scales and temperatures. We present examples of benchmark scenarios that allow for electroweak symmetry nonrestoration all the way up to hundreds of TeV temperatures and also feature suppressed sphaleron washout factors down to the electroweak scale. Our method for transmitting the Standard Model broken electroweak symmetry to an inert Higgs sector has several intriguing implications for (electroweak) baryogenesis and early universe thermal histories and can be scrutinized through Higgs physics phenomenology and electroweak precision measurements at the HL-LHC

Evaluation of Cloud Microphysical Properties Derived from MODIS and Himawari-8 Using In-Situ Aircraft Measurements over the Southern Ocean

Cloud microphysical properties from aircraft measurements during the Southern Ocean Clouds, Radiation, Aerosol Transport Experimental Study are used to evaluate the cloud products from the geostationary satellite Himawari‐8 (H‐8) and the polar‐orbiting satellite the Moderate Resolution Imaging Spectroradiometer (MODIS). Compared to the in situ aircraft observations when aircraft flew horizontally near cloud tops, the cloud droplet effective radius (r_e) and number concentration (N_d) from H‐8 (MODIS) are 33% (26%–31%) and 2% (9–13%) larger. Both the H‐8 and MODIS retrievals behave similarly for liquid‐only and mixed‐phase low‐level clouds, indicating the weak sensitivity of the satellite cloud retrieval performance to cloud phase. The r_e and N_d of the cloud profiles from aircraft measurements were also used to compare with the satellite product. It shows that H‐8 r_e and N_d agree better with aircraft measurements when considering only the in situ data acquired in the upper portions (highest 20%) of the clouds. Roughly, the r_e overestimation by H‐8 decreases from 18% to 3% when considering the upper portions of clouds compared to all cloud layer averages, except for one case with drizzles appeared. In addition, the performance of MODIS r_e and N_d is highly dependent on the wavelengths the retrieval method uses. The droplet r_e retrievals using wavelength of 1.6 μm have much larger biases than that using the other two channels. The potential effects of the cloud vertical variation and the photon penetration depth, the cloud heterogeneity, the cloud droplet size spectra, and the drizzle on satellite retrievals have also been discussed

Evaluation of Cloud Microphysical Properties Derived from MODIS and Himawari-8 Using In-Situ Aircraft Measurements over the Southern Ocean

Cloud microphysical properties from aircraft measurements during the Southern Ocean Clouds, Radiation, Aerosol Transport Experimental Study are used to evaluate the cloud products from the geostationary satellite Himawari‐8 (H‐8) and the polar‐orbiting satellite the Moderate Resolution Imaging Spectroradiometer (MODIS). Compared to the in situ aircraft observations when aircraft flew horizontally near cloud tops, the cloud droplet effective radius (r_e) and number concentration (N_d) from H‐8 (MODIS) are 33% (26%–31%) and 2% (9–13%) larger. Both the H‐8 and MODIS retrievals behave similarly for liquid‐only and mixed‐phase low‐level clouds, indicating the weak sensitivity of the satellite cloud retrieval performance to cloud phase. The r_e and N_d of the cloud profiles from aircraft measurements were also used to compare with the satellite product. It shows that H‐8 r_e and N_d agree better with aircraft measurements when considering only the in situ data acquired in the upper portions (highest 20%) of the clouds. Roughly, the r_e overestimation by H‐8 decreases from 18% to 3% when considering the upper portions of clouds compared to all cloud layer averages, except for one case with drizzles appeared. In addition, the performance of MODIS r_e and N_d is highly dependent on the wavelengths the retrieval method uses. The droplet r_e retrievals using wavelength of 1.6 μm have much larger biases than that using the other two channels. The potential effects of the cloud vertical variation and the photon penetration depth, the cloud heterogeneity, the cloud droplet size spectra, and the drizzle on satellite retrievals have also been discussed

Quantitative decision making in land banking: a Monte Carlo simulation for China's real estate developers

The real estate industry is one of the fast growing industries in many developing countries such as China and India. The Chinese real estate industry has gone through many reforms from offering housing as part of its social welfare system, to the current capitalist model based on demand and supply. Due to these reforms and the shortage of lands for development in China's urban cities, many Chinese property firms have resorted to land banking in order to secure land property for future developments. However, in China, land speculation is considered illegal, while failure to purchase the suitable land for future developments will hinder the real estate developers’ future business and growth. The purpose of this paper is to develop a decision making model for property developments in their land banking decisions and strategies. The paper employed mathematical modeling and Monte Carlo simulation to examine our decision model, and further validated our results by conducting the simulation by using China Vanke Co. Ltd as a case study. This study is one of the first few studies that develop a decision model for land banking in China. It also helps real estate enterprises to make rational and dynamic decision in the current dynamic property market. First Publish Online: 19 Dec 201

Genome-wide transcriptome analysis of gametophyte development in Physcomitrella patens

<p>Abstract</p> <p>Background</p> <p>Regulation of gene expression plays a pivotal role in controlling the development of multicellular plants. To explore the molecular mechanism of plant developmental-stage transition and cell-fate determination, a genome-wide analysis was undertaken of sequential developmental time-points and individual tissue types in the model moss <it>Physcomitrella patens </it>because of the short life cycle and relative structural simplicity of this plant.</p> <p>Results</p> <p>Gene expression was analyzed by digital gene expression tag profiling of samples taken from <it>P. patens </it>protonema at 3, 14 and 24 days, and from leafy shoot tissues at 30 days, after protoplast isolation, and from 14-day-old caulonemal and chloronemal tissues. In total, 4333 genes were identified as differentially displayed. Among these genes, 4129 were developmental-stage specific and 423 were preferentially expressed in either chloronemal or caulonemal tissues. Most of the differentially displayed genes were assigned to functions in organic substance and energy metabolism or macromolecule biosynthetic and catabolic processes based on gene ontology descriptions. In addition, some regulatory genes identified as candidates might be involved in controlling the developmental-stage transition and cell differentiation, namely MYB-like, HB-8, AL3, zinc finger family proteins, bHLH superfamily, GATA superfamily, GATA and bZIP transcription factors, protein kinases, genes related to protein/amino acid methylation, and auxin, ethylene, and cytokinin signaling pathways.</p> <p>Conclusions</p> <p>These genes that show highly dynamic changes in expression during development in <it>P. patens </it>are potential targets for further functional characterization and evolutionary developmental biology studies.</p