29,162 research outputs found
Watada, E. et al., and Kobayashi, T.
No full textData for our paper in Mol Cell Biol (2020) "Age-dependent ribosomal DNA variations in mice
Finding a Maximum Restricted t-Matching via Boolean Edge-CSP
No full textThe problem of finding a maximum 2-matching without short cycles has received significant attention due to its relevance to the Hamilton cycle problem. This problem is generalized to finding a maximum t-matching which excludes specified complete t-partite subgraphs, where t is a fixed positive integer. The polynomial solvability of this generalized problem remains an open question. In this paper, we present polynomial-time algorithms for the following two cases of this problem: in the first case the forbidden complete t-partite subgraphs are edge-disjoint; and in the second case the maximum degree of the input graph is at most 2t-1. Our result for the first case extends the previous work of Nam (1994) showing the polynomial solvability of the problem of finding a maximum 2-matching without cycles of length four, where the cycles of length four are vertex-disjoint. The second result expands upon the works of Bérczi and Végh (2010) and Kobayashi and Yin (2012), which focused on graphs with maximum degree at most t+1. Our algorithms are obtained from exploiting the discrete structure of restricted t-matchings and employing an algorithm for the Boolean edge-CSP
Structural determination of metallofullerene SC3C82 revisited: A surprising finding
No full textPT: J; CR: AKASAKA T, 2000, J AM CHEM SOC, V122, P9316 AKASAKA T, 2001, J PHYS CHEM B, V105, P2971 AKASAKA T, 2002, ENDOFULLERENES NEW F BECKE AD, 1988, PHYS REV A, V38, P3098 BECKE AD, 1993, J CHEM PHYS, V98, P5648 CHAI Y, 1991, J PHYS CHEM-US, V95, P7564 FOWLER PW, 1995, ATLAS FULLERENES, P255 FRANCL MM, 1982, J CHEM PHYS, V77, P3654 HAY PJ, 1985, J CHEM PHYS, V82, P299 HEATH JR, 1985, J AM CHEM SOC, V107, P7779 KATO T, 1995, J PHYS CHEM-US, V99, P856 KOBAYASHI K, 1999, CHEM PHYS LETT, V313, P45 KOBAYASHI K, 2002, CHEM PHYS LETT, V362, P373 LEE C, 1988, PHYS REV B, V37, P785 NAGASE S, 1997, J MOL STRUC-THEOCHEM, V398, P221 NISHIBORI E, 1998, CHEM PHYS LETT, V298, P79 NISHIBORI E, 2000, CHEM PHYS LETT, V330, P497 NISHIBORI E, 2001, ANGEW CHEM INT EDIT, V40, P2998 NISHIBORI E, 2004, PHYS REV B, V69 SHINOHARA H, 1992, NATURE, V357, P52 SHINOHARA H, 1994, J PHYS CHEM-US, V98, P8597 STEVENSON S, 1999, NATURE, V401, P55 SUN BY, 2005, ANGEW CHEM INT EDIT, V44, P4568 TAKATA M, 1995, NATURE, V377, P46 TAKATA M, 1997, PHYS REV LETT, V78, P3330 TAKATA M, 1999, PHYS REV LETT, V83, P2214 TAKATA M, 2003, STRUCT CHEM, V14, P23 TAKATA M, 2004, STRUCT BOND, V109, P59 VANLOOSDRECHT PHM, 1994, PHYS REV LETT, V73, P3415 WAKAHARA T, 2002, CHEM PHYS LETT, V360, P235 WAKAHARA T, 2004, J AM CHEM SOC, V126, P4883 WANG CR, 2000, NATURE, V408, P426 WANG CR, 2001, ANGEW CHEM INT EDIT, V40, P397 YANNONI CS, 1992, SCIENCE, V256, P1191; NR: 34; TC: 6; J9: J AM CHEM SOC; PG: 2; GA: 966RQSource type: Electronic(1
Axionlike Origin of the Primordial Density Perturbation
No full textWe show that an axionlike field coupled to a new confining gauge group can generate the primordial density perturbation in the postinflation Universe. The axion decay constant and strong coupling scale are uniquely determined by observations of the density perturbation, which further suggest a temporal deconfinement of the gauge group after inflation. The resulting temperature-dependent axion potential, together with its periodic nature, gives rise to the red-tilted density perturbation, with a positive local-type non-Gaussianity of order unity
Density perturbations from curvatons revisited
No full textWe investigate density perturbations sourced by a curvaton with a generic energy potential. The key feature of a curvaton potential which deviates from a quadratic is that the curvaton experiences a non-uniform onset of its oscillation. This sources additional contributions to the resulting density perturbations, and we especially find that curvaton potentials that are flatter compared to a quadratic lead to enhancement of the linear and second-order density perturbations, while steepened potentials can generate strongly scale-dependent non-Gaussianity. As such examples, we study pseudo-Nambu- Goldstone curvatons and self-interacting curvatons. Our analyses are analytic, and thus provide a systematic framework for studying curvatons in general. The discussion in this paper are based on [1, 2]. © Published under licence by IOP Publishing Ltd
Large Tensor-to-Scalar Ratio in Small-Field Inflation
No full textWe show that density perturbations seeded by the inflaton can be suppressed when having additional light degrees of freedom contributing to the production of perturbations. The inflaton fluctuations affect the light field dynamics by modulating the length of the inflationary period and, hence, produce additional density perturbations in the postinflationary era. Such perturbations can cancel those generated during inflation as both originate from the same inflaton fluctuations. This allows production of large gravitational waves from small-field inflation, which is normally forbidden by the Lyth bound on the inflaton field excursion. We also find that the field bound is taken over by the light scalar when the inflaton-induced perturbations are suppressed and, thus, present a generalized form of the Lyth bound that applies to the total field space. The novel mechanism allows violation of the usual consistency relation r≤-8nT for the tensor spectral index. © 2013 American Physical Society
Runnings in the curvaton
No full textWe investigate the scale-dependence, or the runnings, of linear and second order density perturbations generated in various curvaton scenarios. We argue that the second order perturbations, i.e. non-Gaussianity, can strongly depend on the scale, even when the linear perturbations are nearly scale-invariant. We present analytic formulae for the runnings from curvatons with general energy potentials, and clarify the conditions under which f NL becomes strongly scale-dependent. From the point of view of the f NL running, curvaton potentials can be classified into roughly two categories by whether the potential flattens or steepens compared to a quadratic one. As such examples, we study pseudo-Nambu-Goldstone curvatons, and self-interacting curvatons, respectively. The dynamics of non-quadratic curvatons and the behaviors of the resulting density perturbations are clarified by analytical methods. Then we also study models where multiple source can be responsible for density perturbations such as the multi-curvaton, and mixed curvaton and inflaton models where the running of f NL can also be large due to their multi-source nature. We make quantitative analysis for each curvaton scenario and discuss in what cases the scale-dependence, in particular, of f NL can be large enough to be probed with future CMB experiments. © 2012 IOP Publishing Ltd and Sissa Medialab srl
Primordial magnetic fields from the post-inflationary universe
No full textWe explore cosmological magnetogenesis in the post-inflationary universe, when the inflaton oscillates around its potential minimum and the universe is effectively dominated by cold matter. During this epoch prior to reheating, large-scale magnetic fields can be significantly produced by the cosmological background. By considering magnetogenesis both during and after inflation, we demonstrate that magnetic fields stronger than 10-15 G can be generated on Mpc scales without having strong couplings in the theory, or producing too large electric fields that would dominate the universe. © 2014 IOP Publishing Ltd and Sissa Medialab srl
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