# Diffusive and Stochastic Processes

### Course content

Stochastic descriptions offer powerful ways to understand fluctuating and noisy phenomena, and are widely used in many disciplines including physics, chemistry, biology, and economics. In this course, basic analytical and numerical tools to analyze stochastic phenomena are introduced and will be demonstrated on several important examples. Students will learn to master stochastic descriptions for analyzing non-equilibrium complex phenomena.

Education

MSc Programme in Physics

MSc Programme in Physics w. minor subject

Learning outcome

Skills
At the conclusion of the course students are expected to be able to:

• Describe diffusion process using Langevin equation and Fokker-Plank equation.
• Solve  several examples of the first passage time problems.
• Explain basic concepts in stochastic integrals, and use it to describe geometric Brownian motions.
• Explain the Poisson process and the birth and death process. Use master equations to describe time evolution and steady state of the processes.
• Explain the relationship between master equations and Fokker-Plank equations using approximation methods such as Kramers-Moyal expansions.
• Explain asymmetric simple exclusion process and related models to describe traffic flow and jamming transition in one-dimensional flows.
• Apply the concepts and techniques to various examples of stochastic phenomena from non-equilibrium complex phenomena.

Knowledge
In this course, the basic tools to analyse stochastic phenomena are introduced by using the diffusion process as one of the most useful examples of stochastic process. The topics include Langevin equations, Fokker-Planck equations,  first passage problems, and master equations. The tools are then used to analyze selected stochastic models that have wide applications to various real phenomena. The topics are chosen from non-equilibrium stochastic phenomena, including geometric Brownian motion (used in e.g. modeling finance), birth and death process (used in e.g. chemical reactions and population dynamics),  and asymmetric simple exclusion process (used in e.g. traffic jam formation). Throughout the course, exercises for analytical calculations and numerical simulations are provided to improve the students' skills.

Competences
This course will provide the students with mathematical tools that have application in range of fields within and beyond physics. Examples of the fields include non-equilibrium statistical physics, biophysics, soft-matter physics, complex systems, econophysics, social physics, chemistry, molecular biology, ecology, etc.  This course will provide the students with a competent background for further studies within the research field, i.e. a M.Sc. project.

Lectures and exercise sessions. Computer exercise included.

Equilibrium statistical physics, physics bachelor level mathematics (Especially: differential and integral calculus, differential equations, Taylor expansions). Basic programming skills.

Academic qualifications equivalent to a BSc degree is recommended.

It is expected that the student brings a laptop with Matlab or other programming environment installed.

ECTS
7,5 ECTS
Type of assessment
Oral examination, 30 min
No preparation time
Aid
Without aids
Marking scale
Censorship form
No external censorship
Several internal examiners
##### Criteria for exam assessment

See Learning outcome

Single subject courses (day)

• Category
• Hours
• Lectures
• 24
• Theory exercises
• 35
• Exam
• 0,5
• Preparation
• 146,5
• English
• 206,0