Official web site of Takeuchi Lab, Univ. Tokyo

Research projects in the Lab

Quest for out-of-equilibrium laws of physics through liquid crystal experiments

Direct observation of 3D dynamics of topological defect lines

We observed topological defects of liquid crystal by confocal microscopy and captured their characteristic topological events, in particular, reconnections.
(to appear)

Ising dynamic scaling laws in liquid crystal

We inspected universal dynamic scaling laws of Model A, which rule ordering processes of, e.g., Ising ferromagnets, by liquid crystal. (to appear)

KPZ universal fluctuations in growing turbulent interfaces

Growing interfaces turned out to be ruled by universal laws linked to various areas of physics and mathematics.

Universal critical phenomenon discovered in topological-defect turbulence

All up once you have entered... The directed percolation universality class, theoretically expected in such a situation, was experimentally found for the first time.

Physics of active matter

Route to turbulence of bacterial suspension

We developed a method to solve a model equation for bacterial suspension with arbitrary boundaries. This allowed us to unveil a characteristic route to turbulence. (to appear)

Emergence of bacterial glass

We discovered that proliferating bacterial populations spontaneously undergo a transition from an active fluid phase to an active glass. (to appear)

Bacterial colony growth and topological defects

We discovered an overlooked role of topological defects in the three-dimensional growth of bacterial colonies. (to appear)

Emergent order in bacterial collective motion

How and when can any order emerge in usually turbulent dense bacterial collective motion? Our experimental findings led to a general framework.

Collective motion of self-propelled colloidal particles

By using active colloids fuelled by an electric field, we explore universal non-equilibrium laws in self-propelled particle systems.

Physical experiments on microbial systems

Extensive microperfusion system (EMPS) for bacterial population experiments

With this new microfluidic device, we can culture and observe bacteria for long time under a uniform condi­tion. Several projects on bacterial populations are ongoing with this device.

Scale invariance in cell size fluctuations

With EMPS, we experi­mentally found universal scaling laws in cell size fluctuations.
(to appear)

Out-of-equilibrium phenomena in macroscopic soft matter systems

Jamming of a spongy granular system

We propose a new model system of largely deformable grains, where we discovered a novel fluid-amorphous transition. (to appear)

Statistical characterization of large chaotic systems

Time-series analysis for measuring instability of large chaotic systems

We develop a new method of time-series analysis for measuring instability of large chaotic systems, applicable when the system is highly symmetric.
(to appear)

New developments on instability analysis

Using Lyapunov vectors that became numerically accessible recently, we characterized collective instability and effective dimensions of large chaotic systems.