Tag: string theory
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What are conformal field theories? (Part 1)
In this series of posts, I will explain what conformal field theories (CFTs) are. Basic familiarity with Quantum Field Theories (QFTs) is assumed. In usual relativistic QFTs have some spacetime symmetries. These symmetries are rotations (one about every space direction), boosts (one along every space direction) and translations (one along every spacetime direction). The set…
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What is supersymmetry?
This post summarizes the main ideas behind supersymmetry. Pre-requisites to read this post include some familiarity with Poincare algebra and basics of quantum field theory (especially the basics of fermions) In relativistic quantum field theory, we have a certain amount of spacetime symmetries. These symmetries include 3 rotational symmetries (along three space directions), 3 boost…
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Some problems that I faced while studying Physics
This is a post in which I am just thinking out loud (writing your thoughts down is a great way to think out loud and organize your thoughts). The things that I write in this post may also be beneficial for some younger student of theoretical physics (which, if true, will be a bonus for…
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AdS3/CFT2 correspondence (Part 2: WZW models)
This is second of my series of posts on AdS3/CFT2 correspondence (for the first post, click here). In this post, I will describe what WZW (Wess-Zumino-Witten) models are. They are relevant here because a WZW model is used to decribe string theory on AdS3 . Basics of field theory, little familiarity with Lie groups and…
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AdS3/CFT2 correspondence (Part 1: AdS3 space)
This is first in a series of posts on duality between strings moving on AdS3 x S3 x T4 spacetime (don’t get intimidated by this) and a conformal field theory living on the boundary of the AdS3 spacetime (which is two dimensional). I will try to explain the basics required to understand this duality. In…
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Why string theory ‘may have’ extra dimensions?
This is a post that tries to answer the question, “How do we come to know that in string theory, there ‘can be’ extra dimensions in space?”. Some basic understanding of quantum field theory and general relativity is assumed as a prerequisite. Firstly, I want to point out why I have written ‘can be’ instead…
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Getting realistic vaccua from string theory (A summary)
This is a small post on how to try to get realistic four-dimensional spacetimes from type IIA and type IIB string theories. I will try to explain the technical points as much as I can. I will assume the knowledge of metric, Ricci, and Riemann tensors and very basic QFT. Let me know if some…
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Why criticizing string theory has become a “cool thing”?
This post explores why critisizing string theory has become a “cool thing” in the last few years.
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Have we found all string theories?
This brief post answers the question, “Have we found all string theories?”. It will require a basic understanding of QFT and symmetry algebras.
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String Theory and M theory compactifications
This is a post about compactifications in superstring theory and M theory. This post is related to my second Ph.D. project. A little familiarity with the Ricci tensor and the word “gauge group” is assumed but I tried to make it self-contained.
Hassaan Saleem 