Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Unrecognizable Black Holes in Two Dimensions   The classical 2D cosmological model of Callan, Giddings, Harvey and
Strominger possesses a global symmetry that is responsible for decoupling of
matter fields. The model is quantized on the basis of the extended phase space
method to allow an exhaustive, algebraic analysis to find potential anomalies.
Under a certain set of reasonable assumptions we show that neither the BRST
symmetry of the theory nor the global symmetry suffers from an anomaly. From
this we conclude that there is nothing to recognize the existence of black hole
and therefore nothing to radiate in their cosmological model.

17
The categories of this paper are: q-fin
22
The categories of this paper are: chao-dyn
4
The categories of this paper are: cond-mat
9
The categories of this paper are: nlin
16
The categories of this paper are: stat
20
The categories of this paper are: acc-phys
23
The categories of this paper are: solv-int
36
The categories of this paper are: cmp-lg
28
The categories of this paper are: alg-geom
0
The categories of this paper are: hep-ph
33
The categories of this paper are: plasm-ph
25
The categories of this paper are: patt-sol
18
The categories of this paper are: econ
37
The categories of this paper are: supr-con
12
The categories of this paper are: nucl-th
34
The categories of this paper are: chem-ph