Demography is a part of social science that studies the structure, evolution, and problems of human population.

Demography is a branch of social science that studies the structure, distribution, and changes in human population.

Tokyo is the city with the highest population density in Japan.

Looking at the population pyramid, you can see that this country is aging.

Graph theory is a branch of mathematics that studies mathematical structures called graphs.

Theoretically, this experiment should succeed.

Information theory is a field of study that mathematically analyzes the amount of information and the efficiency of its transmission.

He is known as an excellent theoretician.

He is immersed in the study of string theory.

He is particularly interested in game theory within economics.