About QFT.org

QFT.org is a connected resource for students and researchers studying quantum field theory. Its aim is to make the subject learnable from first principles and useful in research: explain the physics, develop the calculations, state their limits, and make the supporting sources easy to check.

Find the right entry point

• Start Here helps you choose a learning route and find any preparation you need.
• Courses develops graduate QFT through lessons and worked problems, based on Jie Ren’s notes of Alexander M. Polyakov’s lectures and expanded with additional explanations and calculations.
• The sixteen subject volumes, available from the Library menu, connect mathematical methods and field-theory foundations to gauge theory, condensed matter, curved spacetime, holography, and mathematical QFT.
• Research examines open problems and the evidence behind current approaches.
• Reference provides shorter routes to terminology, notation, formulas, models, and sources, with links to fuller treatments.

The site is revised as errors are identified, explanations are improved, and new evidence becomes available. Research treatments distinguish established results from approximations, conjectures, and open questions.

Maintenance and scientific editing

QFT.org is maintained by Jie Ren, with AI assistance for writing, calculations, source comparison, and technical development.

AI assistance can miss errors. The editorial standards emphasize explicit assumptions, checked derivations, suitable sources, reproducible calculations, and corrections informed by reader feedback.

Contact, citation, and privacy

Email renphysics@qft.org to report a scientific error, an accessibility barrier, a broken link, or a useful improvement. Include the page address and the relevant passage or equation.

For scholarly use, see Citing and reusing QFT.org. The Privacy policy explains site analytics, browser features, and email contact.