Welcome to my website!

My name is Jakub Cehula, and I am a master's student of Theoretical Physics at Charles University in Prague. I am also a member of Time-domain astronomy group of Ondřej Pejcha. Before working in the field of astronomy, I worked in the field of continuum mechanics under my supervisor Vít Průša.

If you wish to contact me, please use my email: jakub.cehula@gmail.com

RESEARCH

If you want to see my publications, please visit my profile on Google Scholar.

Stability of stars undergoing rapid mass loss

When a star in a binary system evolves and expands, it can transfer mass to its companion. If the mass loss proceeds on dynamical timescale, the binary can undergo a catastrophic interaction accompanied by tremendous loss of mass, angular momentum, and energy. This common envelope evolution phase is a crucial step in the formation of close binaries composed of compact objects (white dwarfs, neutron stars, black holes), which includes progenitors of gravitational wave sources detected by LIGO.

My goal is to deepen the understanding of stability of binary stars to dynamic mass loss, in particular to determine updated conditions of instability for a wide range of stars.

Origami-like structures made of light activated shape memory polymers

Light activated shape memory polymers (LASMPs) are smart materials with the ability of remembering a deformed state (temporary shape) due to exposure to UV light and returning to the permanent (original) shape by the exposure to UV light with a different wavelength. Regarding the shape of smart materials frequent inspiration is taken from the art of origami, the Japanese art of folding paper into various shapes.

I have developed a code for computer modelling of such origami-like structures made of LASMPs, see (Cehula & Průša 2020, Int. J. Eng. Sci. 150, 103235). The code is a modification to the state-of-the-art code for simulations of elastic origami-like structures developed by (Liu & Paulino 2018, Origami, 7, 1167-1182). The original code is called MERLIN2, my modification is called MERLIN2.LUX.

MISCELLANEOUS

Talk at MathMAC seminar: Deformations of light-activated shape memory polymers. Presentation: [pdf], [pptx].

Relativistic physics II: The generation of gravitational waves in linearized theory. Notes for classmates (in Slovak): [pdf].