Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Backward difference formula: The energy technique for subdiffusion
  equation   Based on the equivalence of A-stability and G-stability, the energy technique
of the six-step BDF method for the heat equation has been discussed in
[Akrivis, Chen, Yu, Zhou, Math. Comp., Revised]. Unfortunately, this theory is
hard to extend the time-fractional PDEs. In this work, we consider three types
of subdiffusion models, namely single-term, multi-term and distributed order
fractional diffusion equations. We present a novel and concise stability
analysis of time stepping schemes generated by $k$-step backward difference
formula (BDF$k$), for approximately solving the subdiffusion equation. The
analysis mainly relies on the energy technique by applying Grenander-Szeg\"{o}
theorem. This kind of argument has been widely used to confirm the stability of
various $A$-stable schemes (e.g., $k=1,2$). However, it is not an easy task for
the higher-order BDF methods, due to the loss the $A$-stability. The core
object of this paper is to fill in this gap.

29
The categories of this paper are: funct-an
22
The categories of this paper are: chao-dyn
4
The categories of this paper are: cond-mat
37
The categories of this paper are: supr-con
30
The categories of this paper are: q-alg
18
The categories of this paper are: econ
33
The categories of this paper are: plasm-ph
19
The categories of this paper are: eess
26
The categories of this paper are: bayes-an
36
The categories of this paper are: cmp-lg
15
The categories of this paper are: nucl-ex
34
The categories of this paper are: chem-ph
23
The categories of this paper are: solv-int
3
The categories of this paper are: physics
20
The categories of this paper are: acc-phys
7
The categories of this paper are: hep-th