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Abstract Ultra-light axion fields, motivated by string theory, form a large condensate (axion cloud) around rotating black holes through superradiant instability. Several effects due to the axion cloud, such as the spin-down of black holes and the emission of monochromatic gravitational waves, open a new window to search for axions by astrophysical observations. When the axion self-interaction is considered, the evolution of clouds is altered significantly, and an explosive phenomenon called a bosenova can happen. Thus, it is necessary to understand the precise evolution of self-interacting clouds for the detection of axions by astrophysical observations. In this paper, we propose a new method to track the whole process of the growth of self-interacting axion clouds employing the adiabatic approximation. We emphasize that our method relies neither on the non-relativistic approximation nor on perturbative treatment of the self-interaction, which is often used in the literature. Our main finding is that the evolution of clouds in the strongly self-interacting regime depends on the strength of the gravitational coupling between the axion and the black hole. For a large coupling, the cloud evolves into a quasi-stationary state where the superradiant energy gain is balanced with the energy dissipation to infinity by the self-interaction. On the other hand, when one decreases the size of the coupling, clouds become unstable at some energy, which would be interpreted as the onset of a bosenova.

Abstract We study quark mass matrices derived from magnetized $T^2/\\mathbb {Z}_2$ orbifold models. Yukawa matrices at three modular fixed points, τ = i, e2πi/3, and i∞, are invariant under S-, ST-, and T-transformations. We study these invariances on the $T^2/\\mathbb {Z}_2$ twisted orbifold. We find that Yukawa matrices have a kind of texture structure, although those at τ = i∞ are not realistic. We classify the Yukawa textures at τ = i and e2πi/3. Moreover we investigate the conditions such that the quark mass matrix constructed by Yukawa textures becomes approximately a rank-one matrix, which is favorable to lead to hierarchical masses between the third generation and the others. It is found that realistic quark mass matrices can be obtained around the S-invariant and ST-invariant vacua. As an illustrative example, we show the realization of the quark mass ratios and mixing based on Fritzch and Fritzch–Xing mass matrices.

DNA methylation has been linked to gene silencing in cancer. Primary effusion lymphoma (PEL) and myeloma are lymphoid malignancies that arise from terminally differentiated B cells. Interestingly, PEL do not express immunoglobulins or most B lineage-specific genes. The B cell-specific B29 (Ig beta /CD79b) gene is silenced in PEL and some myelomas but is expressed in other normal and malignant B cells. B29 expression was reactivated in PEL by demethylating and histone deacetylase inhibiting treatments. Bisulfite sequencing revealed two types of DNA methylation in silenced B29 promoters: at conventional CpG and at CC(A/T)GG B29 promoter sites. The pattern of methylated CpG (CpG) and CC(A/T)GG B29 promoter methylation observed was similar to that recently reported for epigenetic silencing of an integrated retrovirus. Methylation of CC(A/T)GG sites in the B29 promoter significantly repressed in vivo transcriptional activity. Also, methylation of a central conserved CCTGG B29 promoter site blocked the binding of early B cell factor. This methylated motif formed DNA-protein complexes with nuclear extracts from all cell types examined. Therefore, CC(A/T)GG methylation may represent an important type of epigenetic marker on mammalian DNA that impacts transcription by altering DNA-protein complex formation.

The 2021 Sveriges Riksbank Prize in Economic Sciences in Memory of Alfred Nobel was awarded to David Card “for his empirical contributions to labour economics”, and to Joshua Angrist and Guido Imbens “for their methodological contributions to the analysis of causal relationships”. Lennart B. Ackermans reflects on Card, Angrist, and Imben's work.

The 2022 Sveriges Riksbank Prize in Economic Sciences in Memory of Alfred Nobel was awarded to Ben Bernanke, Douglas Diamond, and Philip Dybvig “for research on banks and financial crises”. Jens van 't Klooster reflects on Bernanke, Diamond, and Dybvig's work.

Abstract In six-dimensional F-theory/heterotic string theory, half-hypermultiplets arise only when they correspond to particular quaternionic Kähler symmetric spaces, which are mostly associated with the Freudenthal–Tits magic square. Motivated by the intriguing singularity structure previously found in such F-theory models with a gauge group SU(6), SO(12), or E7, we investigate, as the final magical example, an F-theory on an elliptic fibration over a Hirzebruch surface of the non-split I6 type, in which the unbroken gauge symmetry is supposed to be Sp(3). We find significant qualitative differences between the previous F-theory models associated with the magic square and the present case. We argue that the relevant half-hypermultiplets arise at the E6 points, where half-hypermultiplets 20 of SU(6) would have appeared in the split model. We also consider the problem on the non-local matter generation near the D6 point. After stating what the problem is, we explain why this is so by using the recent result that a split/non-split transition can be regarded as a conifold transition.

We perform imaging of a fundamental string from string scattering amplitudes, and show that its image is a double slit.

Abstract We examine interacting bosonic higher-spin gauge fields in the BRST-antifield formalism. Assuming that an interacting action $S$ is a deformation of the free action with a deformation parameter $g$, we solve the master equation $(S,S)=0$ from the lower orders in $g$. It is shown that, choosing a certain cubic interaction as the first-order deformation, we can solve the master equation and obtain an action containing all orders in $g$. The antighost number of the action obtained is less than or equal to two. Furthermore, we show that the action obtained is lifted to that of interacting bosonic higher-spin gauge fields on anti-de Sitter spaces.

Abstract We review some aspects of Nambu mechanics on the basis of works previously published separately by the present author. The main focuses are on three themes: the various symmetry structures, their possible relevance to string/M-theory, and a Hamilton–Jacobi-like reformulation. We try to elucidate the basic ideas, most of which were rooted in more or less the same ground, and to explain the motivations behind these works from a unified and vantage viewpoint. Various unsolved questions are mentioned. We also include a historical account of the genesis of Nambu mechanics, and discuss (in the appendix) some parallelism of various ideas behind Nambu’s paper with Dirac’s old works which are related to the description of vortical flows in terms of gauge potentials.