Featured Paper of the Week
2020-04-20
Black Hole as a Quantum Field Configuration
What's going on inside black holes? The observations to date have taught us the nature of black holes outside and around it, but it does not tell us anything about the inside yet. This is because blac...more
2020-01-24
Distance between collapsing matter and trapping horizon in evaporating black holes
How deep can an apple fall into the horizon of a black hole? Of course, in the case of a classic black hole, the apple reaches the center. However, the real world is described by quantum theory, and b...more
2020-01-09
Akizuki-Nakano vanishing theorem and its application for globally F-split 3-folds
In algebraic geometry, it is important to study spaces (=varieties) which may admit singular points. "Smoothing" is an effective way to deal with singularities. Roughly speaking, a smoothing of a (sin...more
2019-07-22
Synthetic dimensions and topological chiral currents in mesoscopic rings
In condensed matter systems, the topological effect of chiral currents is intimately related to two-dimensional systems. Recently emerging concept of "synthetic dimensions" provides a way to explore t...more
2019-07-16
The KO-valued spectral flow for skew-adjoint Fredholm operators
Spectral flow measures the number of eigenvalue crossings of continuous paths of Fredholm operators (which have finite-dimensional kernels). Atiyah, Patodi and Singer first defined spectral flow as a ...more
2019-07-09
Instantons in Chiral Magnets
More than 50 years ago, Russian physicist Dzyaloshinsky has proposed the specific interaction in some kinds of magnets to explain weak ferromagnetic behavior of them, and soon after that, Professor Mo...more
2019-07-04
Rigidity of the mod 2 families Seiberg-Witten invariants and topology of families of spin 4-manifolds
After the early 1980s, gauge theory has been used by mathematicians to study 4-dimensional spaces (manifolds). The hottest mathematical subject studied by gauge theory is a sort of difference between ...more
2019-06-13
Probing localization and quantum geometry by spectroscopy
Localization has been one of the main topics of interest in condensed matter physics for more than half a century. Study of localizatoin has recently been entering into a new stage because of the deve...more
2019-05-28
Uncovering critical properties of the human respiratory syncytial virus by combining in vitro assays and in silico analyses
When a virion is left in a liquid medium over some time, it loses its ability to infect cells. This is often because the virion surface proteins become deformed, e.g. because of heat or the ionic cont...more
2019-05-15
Comments on holographic entanglements in cutoff AdS
AdS/CFT correspondence tells us that a gravity in AdS space is equivalent to CFT which lives on the boundary of the AdS. Recently it has been proposed that an integrable TT deformation of CFTs produce...more
2019-03-12
Diffusive Nambu-Goldstone modes in quantum time-crystals
Symmetry and its breaking is one of the most important notions in modern physics. It is known that when a continuum symmetry is spontaneously broken, there appears a gapless excitation called the Namb...more
2019-03-06
Non-sinusoidal Waveform in Temperature-Compensated Circadian Oscillations
We have autonomous daily rhythm in our body, so-called “circadian clock” for which we can wake up without alarm clock. The rhythm governs the timing of physiological events such as hormone secretion. ...more
2019-02-07
Quantum annealing for polynomial systems of equations
The advent of Noisy Intermediate-Scale Quantum (NISQ) quantum computers has galvanized efforts towards discovering near-term applications. An algorithm for solving polynomial systems of equations was ...more
2019-01-31
Back Reaction of 4D Conformal Fields on Static Geometry
In classical mechanics, a black hole is described by a vacuum solution with the horizon of the Einstein equation. For spherical case, it is the Schwarzschild metric, and the location of the horizon is...more
2019-01-22
Index theory and topological phases of aperiodic lattices
The paper studies the interactions between dynamical systems, represented via groupoid operator algebras, and index theory, described using Kasparov's bivariant K-functor. The key motivating example i...more
2018-11-30
Engaging the Public with Supernova and Supernova Remnant Research Using Virtual Reality
On April 21, 2018, residents of Wako came to RIKEN for the Open Day. Over one hundred people visited the exhibit of the Astrophysical Big Bang Laboratory (ABBL) and interacted with real scientific da...more
2018-11-12
Gamow-Teller transitions from high-spin isomers in $N=Z$ nuclei
Atomic nuclei are composed of protons and neutrons. We may imagine like a certain number of (quantum) balls putting in a (self-bound) container. On the one hand, the nuclear magic numbers show the sin...more
2018-11-02
Effective field theory of time-translational symmetry breaking in nonequilibrium open system
Although we know "all things are in a state of flux. (Patna rhei.)", it has been still an interesting question whether we have "universal" features in such time-evolution of all things. Considering th...more
2018-10-18
Non-equilibrium Chiral Magnetic/Vortical Effects in Viscous Fluids
Chiral magnetic and vortical effects are novel effects in quantum fluids with chiral anomaly. We utilize the chiral kinetic theory in a relaxation-time approximation to investigate the nonlinear anoma...more
2018-10-09
Online Model Parameter Estimation With Ensemble Data Assimilation in the Real Global Atmosphere
When and where will it rain, and how heavy? – this is a central question that meteorology tries to address. Numerical weather prediction (NWP) is a major approach using data assimilation with mathemat...more