1,069 research outputs found

    Nuclear reaction path and requantization of TDDFT

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    Using a theory of large amplitude collective motion, the adiabatic self-consistent collective coordinate method, we derive reaction path for the fusion process at sub-barrier energies. The collective Hamiltonian to describe the fusion process is constructed, based on the obtained reaction path and canonical variables. We study the reaction of N=Z stable nuclei, alpha+16O, 16O+16O, and alpha+12C. The results suggest that, after two nuclei touch, the reaction path is significantly deviated from the simple relative motion, which may affect the deep sub-barrier fusion cross section.Comment: 8 pages, 2 figures, Proceedings of IIRC symposium "Perspectives of the Physics of Nuclear Structure

    Statistically-Anisotropic Tensor Bispectrum from Inflation

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    We develop a possibility of generating tensor non-Gaussianity in a kind of anisotropic inflation, where a U(1)U(1) gauge field is kinetically coupled to a spectator scalar field. Owing to this coupling, the coherent mode of the electric field appears and softly breaks the isotropy of the Universe. We compute the bispectrum of linearly-polarized tensor perturbations sourced by the gauge field and find that it is strongly red-tilted and has distinctive statistical anisotropies including higher-order multipole moments. Interestingly, the tensor bispectra with the specific combinations of linear polarization modes are dominant, and their amplitudes depend on the different sets of multipole moments. This new type of statistically-anisotropic tensor non-Gaussianity can be potentially testable with the upcoming cosmic microwave background B-mode polarization experiments.Comment: 25 pages, 4 figure

    Idiopathic Retroperitoneal Hematoma

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    A 34-year-old female presented with sudden onset of severe abdominal pain in a flank distribution. A large mass was palpable in the right upper quadrant on physical examination. Abdominal contrast-enhanced computed tomography showed a well-defined, right-sided, retroperitoneal cystic lesion located between the abdominal aorta and the inferior vena cava (IVC). The tumor size was 55 Γ— 58 mm, and it compressed the gallbladder and the duodenum. Upper gastrointestinal radiography revealed a stricture of the second portion of the duodenum by the tumor. T2-weighted magnetic resonance imaging showed that the whole part was hyperintense with hypointense rims, but the inner was partially hypointense. Based on the radiological findings, the preoperative differential diagnosis included retroperitoneal teratoma, Schwannoma, abscess, and primary retroperitoneal tumor. On laparotomy, the tumor was located in the right retroperitoneal cavity. Kocher maneuver and medial visceral rotation, which consists of medial reflection of the upper part of right colon and duodenum by incising their lateral peritoneal attachments, were performed. Although a slight adhesion to the IVC was detected, the tumor was removed safely. Thin-section histopathology examination detected neither tumor tissues nor any tissues such as adrenal gland, ovarian tissue, or endometrial implants. The final pathological diagnosis was idiopathic retroperitoneal hematoma; the origin of the bleeding was unclear. The patient was discharged without any complication 5 days after the operation

    On the Impossibility of Post-Quantum Black-Box Zero-Knowledge in Constant Rounds

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    We investigate the existence of constant-round post-quantum black-box zero-knowledge protocols for NP\mathbf{NP}. As a main result, we show that there is no constant-round post-quantum black-box zero-knowledge argument for NP\mathbf{NP} unless NPβŠ†BQP\mathbf{NP}\subseteq \mathbf{BQP}. As constant-round black-box zero-knowledge arguments for NP\mathbf{NP} exist in the classical setting, our main result points out a fundamental difference between post-quantum and classical zero-knowledge protocols. Combining previous results, we conclude that unless NPβŠ†BQP\mathbf{NP}\subseteq \mathbf{BQP}, constant-round post-quantum zero-knowledge protocols for NP\mathbf{NP} exist if and only if we use non-black-box techniques or relax certain security requirements such as relaxing standard zero-knowledge to Ο΅\epsilon-zero-knowledge. Additionally, we also prove that three-round and public-coin constant-round post-quantum black-box Ο΅\epsilon-zero-knowledge arguments for NP\mathbf{NP} do not exist unless NPβŠ†BQP\mathbf{NP}\subseteq \mathbf{BQP}.Comment: 46 page
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