Complex Fermatean fuzzy geometric aggregation operators and their application on group decision-making problem based on Einstein T-norm and T-conorm

Complex Fermatean fuzzy set (CFF-Sets) is one of the successful extensions of complex Pythagorean fuzzy sets (CPF-Sets). The main objective of the paper is to present complex Fermatean fuzzy sets (CFF-Sets), complex Fermatean fuzzy numbers (CFFNs) and some of their basic operational laws and their corresponding aggregation operators, which can represent the time-periodic problems and two-dimensional information in a single set. We introduce various novel operators, such as complex Fermatean fuzzy Einstein weighted geometric aggregation (CFFEWGA) operator, complex Fermatean fuzzy Einstein ordered weighted geometric aggregation (CFFEOWGA) operator, complex Fermatean fuzzy Einstein hybrid geometric aggregation (CFFEHGA) operator, induced complex Fermatean fuzzy Einstein ordered weighted geometric aggregation (I-CFFEOWGA) operator, and induced complex Fermatean fuzzy Einstein hybrid geometric aggregation (I-CFFEHGA) operator along with their structure properties, such as idempotency, boundedness and monotonicity. An illustrative example related to the selection of the more suitable location for hospital is to be considered to show the effectiveness and efficiency of the novel approach. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2024.