<｜begin▁of▁sentence｜>### Instruction:
Given the high-energy theory collaborations graph from a GML file named hep-th.gml, can the EM (Expectation Maximization) algorithm be used to detect community structures assuming we want to discover 3 communities? Furthermore, can you provide a JSON representation of the identified community structure?
### Response:
import networkx as nx
from cdlib import algorithms

# Create and analyze a graph from a GML file
G = nx.read_gml('hep-th.gml')

# Use the EM algorithm to detect communities, assuming a desire for 3 clusters
communities = algorithms.em(G, k=3)

# Export the community structure in JSON format
community_json = communities.to_json()

print(community_json)
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