{'fraction_non_alphanumeric': 0.025, 'fraction_numerical': 0.004166666666666667, 'mean_word_length': 5.328947368421052, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
1/Nc EXPANSION FOR THE PARTITION FUNCTION IN FOUR-FERMION MODELS

We present a derivation of the bosonic contribution to the thermodynamical potential of four-fermion models by means of a 1/Nc-expansion of the functional integral defining the partition function. This expansion turns out to be particularly useful in correcting the mean field approximation especially at low temperatures, where the relevant degrees of freedom are low-mass bosonic excitations (pseudo-Goldstones).