367 research outputs found

    Standard Embeddings of Smooth Schubert Varieties in Rational Homogeneous Manifolds of Picard Number 1

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    Smooth Schubert varieties in rational homogeneous manifolds of Picard number 1 are horospherical varieties. We characterize standard embeddings of smooth Schubert varieties in rational homogeneous manifolds of Picard number 1 by means of varieties of minimal rational tangents. In particular, we mainly consider nonhomogeneous smooth Schubert varieties in symplectic Grassmannians and in the 20-dimensional F4F_4-homogeneous manifold associated to a short simple root.Comment: 22 page

    K\"ahler-Einstein metrics on smooth Fano toroidal symmetric varieties of type AIII

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    The wonderful compactification XmX_m of a symmetric homogeneous space of type AIII(2,m)(2,m) for each m≥4m \geq 4 is Fano, and its blowup YmY_m along the unique closed orbit is Fano if m≥5m \geq 5 and Calabi-Yau if m=4m = 4. Using a combinatorial criterion for K-stability of smooth Fano spherical varieties obtained by Delcroix, we prove that XmX_m admits a K\"ahler-Einstein metric for each m≥4m \geq 4 and YmY_m admits a K\"ahler-Einstein metric if and only if m=4,5m = 4,5.Comment: 20 pages, 6 figures. arXiv admin note: text overlap with arXiv:2011.12551, arXiv:2203.1105

    K-stability of Gorenstein Fano group compactifications with rank two

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    We give a classification of Gorenstein Fano bi-equivariant compactifications of semisimple complex Lie groups with rank two, and determine which of them are equivariant K-stable and admit (singular) K\"{a}hler-Einstein metrics. As a consequence, we obtain several explicit examples of K-stable Fano varieties admitting (singular) K\"{a}hler-Einstein metrics. We also compute the greatest Ricci lower bounds, equivalently the delta invariants for K-unstable varieties. This gives us three new examples on which each solution of the K\"{a}hler-Ricci flow is of type II.Comment: 33 pages, 8 figure

    K\"{a}hler-Einstein metrics on smooth Fano symmetric varieties with Picard number one

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    Symmetric varieties are normal equivarient open embeddings of symmetric homogeneous spaces, and they are interesting examples of spherical varieties. We prove that all smooth Fano symmetric varieties with Picard number one admit K\"{a}hler-Einstein metrics by using a combinatorial criterion for K-stability of Fano spherical varieties obtained by Delcroix. For this purpose, we present their algebraic moment polytopes and compute the barycenter of each moment polytope with respect to the Duistermaat-Heckman measure.Comment: 13 pages, 6 figure

    Placenta Therapy: Its Biological Role of Anti-Inflammation and Regeneration

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    Human placental extract has been used to treat fatigue, postmenopausal symptoms, wound healing, and growth retardation in Korea. Combined with acupuncture therapy, placental extract extends its therapeutic limit to pain control. Recently, we have reported acupuncture point injection (API) with placental extract modulated inflammation-involving pain symptoms in chronic pain diseases. In order to rehabilitate patients suffering from chronic pain and restricted joint mobility, placental extract was injected into acupuncture points localized on the joints, surrounding muscles acting in concert with the joints, and paravertebral muscles affecting the innervation of the joints. Here, we describe the pathology of pain syndromes including neck pain, back pain, shoulder pain, knee arthritis, fibromyalgia, and complex regional pain syndrome and propose methodology of APIs with placental extract in treating these pain diseases

    Gating of memory encoding of time-delayed cross-frequency MEG networks revealed by graph filtration based on persistent homology

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    To explain gating of memory encoding, magnetoencephalography (MEG) was analyzed over multi-regional network of negative correlations between alpha band power during cue (cue-alpha) and gamma band power during item presentation (item-gamma) in Remember (R) and No-remember (NR) condition. Persistent homology with graph filtration on alpha-gamma correlation disclosed topological invariants to explain memory gating. Instruction compliance (R-hits minus NR-hits) was significantly related to negative coupling between the left superior occipital (cue-alpha) and the left dorsolateral superior frontal gyri (item-gamma) on permutation test, where the coupling was stronger in R than NR. In good memory performers (R-hits minus false alarm), the coupling was stronger in R than NR between the right posterior cingulate (cue-alpha) and the left fusiform gyri (item-gamma). Gating of memory encoding was dictated by inter-regional negative alpha-gamma coupling. Our graph filtration over MEG network revealed these inter-regional time-delayed cross-frequency connectivity serve gating of memory encoding
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