Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Leading gradient correction to the kinetic energy for two-dimensional
  fermion gases   Density functional theory (DFT) is notorious for the absence of gradient
corrections to the two-dimensional (2D) Thomas-Fermi kinetic-energy functional;
it is widely accepted that the 2D analog of the 3D von Weizs\"acker correction
vanishes, together with all higher-order corrections. Contrary to this
long-held belief, we show that the leading correction to the kinetic energy
does not vanish, is unambiguous, and contributes perturbatively to the total
energy. This insight emerges naturally in a simple extension of standard DFT,
which has the effective potential energy as a functional variable on equal
footing with the single-particle density.

21
The categories of this paper are: adap-org
23
The categories of this paper are: solv-int
10
The categories of this paper are: q-bio
32
The categories of this paper are: atom-ph
28
The categories of this paper are: alg-geom
24
The categories of this paper are: dg-ga
18
The categories of this paper are: econ
14
The categories of this paper are: math-ph
7
The categories of this paper are: hep-th
26
The categories of this paper are: bayes-an
22
The categories of this paper are: chao-dyn
6
The categories of this paper are: astro-ph
11
The categories of this paper are: hep-lat
0
The categories of this paper are: hep-ph
19
The categories of this paper are: eess
17
The categories of this paper are: q-fin