Arxiv is an open-access electronic preprint library, which contains papers in many fields such as mathematics, physics, computer science, biology, statistics and economics. The difficulty of reading Arxiv's thesis mainly depends on the following factors:

1. Topic: If you have a deep understanding of the topic, it will be relatively easy to read. On the other hand, if you know nothing about the topic of the paper, it will be more difficult to read.

2. Paper quality: The quality of papers on Arxiv is uneven. Some papers are very clear, logical and easy to understand; However, some papers may have some problems such as unclear language expression and imprecise argumentation, so it will be more difficult to read.

3. Paper form: There are various papers on Arxiv, including plain text, LaTeX, PDF, etc. If you are familiar with the format used in the paper, you will read it more smoothly.

4. Your reading ability: This is also a very important factor. If your reading ability is strong, then you can understand and absorb the content of the paper faster; On the contrary, if your reading ability is weak, it will be more difficult to read.

Generally speaking, the reading difficulty of Arxiv's papers is not fixed, but varies from person to person. If you want to improve your ability to read Arxiv papers, I suggest you start from the following aspects: First, try to choose topics that interest you; Secondly, read more high-quality papers and learn their writing style and argumentation methods; Finally, constantly improve your English level and professional knowledge.