A large area of modern physics is covered by high energy physics. Research fields like cosmic rays, dark matter, neutrino physics, and so forthare subjects of interest for many scientists over the world. Together with experimental physics, Monte-Carlo simulations represent very important and useful tools for the understanding of many phenomena. During the last decades, more simulation codes have been developed. Some of them focused on general aspects of fundamental research (GEANT 4, FLUKA, etc.) and some directly focused on different areas of interest (e.g., CORSIKA, AIRES—cosmic rays; GENIE—neutrino physics; etc.). Each simulation code is based on several interaction models at high or low energy (e.g., QGSJET, EPOS, QGSP, etc.). Each model is based on the results obtained at different laboratories over the world, and the parameters are extrapolated to energies higher than an experiment could reach.

The main goal of this special issue is to bring together important information about modern simulation codes and computational methods such as Monte-Carlo toolsand interaction models. Experimental results compared with the one obtained with different simulation tools are also welcome.

We invite scientists active in the field to contribute with original research papers or review papers (both experimental and theoretical), which include, but are not limited to:

• Methods, algorithms, and codes
• Monte-Carlo simulation techniques
• Astrophysics and cosmic rays
• Hadronic interaction models
• Neutrino physics
• Cosmology
• Dark matter and energy
• Related nonlinear mathematical models and methods

Before submission authors should carefully read over the journal’s Author Guidelines, which are located at http://www.hindawi.com/journals/ahep/guidelines/. Prospective authors should submit an electronic copy of their complete manuscript through the journal Manuscript Tracking System at http://mts.hindawi.com/submit/journals/ahep/compm/ according to the following timetable: