WE PROPOSE TO USE CURRENT ALL--SKY DATA ON GALAXY CLUSTERS IN THE RADIO/INFRARED BANDS IN ORDER TO CONSTRAIN COSMOLOGY. THIS WILL BE ACHIEVED PERFORMING PARAMETER ESTIMATION WITH NUMBER COUNTS AND POWER SPECTRA FOR GALAXY CLUSTERS DETECTED BY PLANCK THROUGH THEIR SUNYAEV--ZELDOVICH SIGNATURE. THE ULTIMATE GOAL OF THIS PROPOSAL IS TO USE CLUSTERS AS TRACERS OF MATTER DENSITY IN ORDER TO PROVIDE INFORMATION ABOUT FUNDAMENTAL PROPERTIES OF OUR UNIVERSE SUCH AS THE LAW OF GRAVITY ON LARGE SCALE EARLY UNIVERSE PHENOMENA STRUCTURE FORMATION AND THE NATURE OF DARK MATTER AND DARK ENERGY. WE WILL LEVERAGE ON THE AVAILABILITY OF A LARGER AND DEEPER CLUSTER CATALOG FROM THE LATEST PLANCK DATA RELEASE IN ORDER TO INCLUDE FOR THE FIRST TIME THE CLUSTER POWER SPECTRUM IN THE COSMOLOGICAL PARAMETER DETERMINATION ANALYSIS. FURTHERMORE WE WILL EXTEND CLUSTERS' ANALYSIS TO COSMOLOGICAL MODELS NOT YET INVESTIGATED BY THE PLANCK COLLABORATION. THESE AIMS REQUIRE A DIVERSE SET OF ACTIVITIES RANGING FROM THE CHARACTERIZATION OF THE CLUSTERS' SELECTION FUNCTION THE CHOICE OF THE COSMOLOGICAL CLUSTER SAMPLE TO BE USED FOR PARAMETER ESTIMATION THE CONSTRUCTION OF MOCK SAMPLES IN THE VARIOUS COSMOLOGICAL MODELS WITH CORRECT CORRELATION PROPERTIES IN ORDER TO PRODUCE RELIABLE SELECTION FUNCTIONS AND NOISE COVARIANCE MATRICES AND FINALLY THE CONSTRUCTION OF THE APPROPRIATE LIKELIHOOD FOR NUMBER COUNTS AND POWER SPECTRA. WE PLAN TO MAKE THE FINAL CODE AVAILABLE TO THE COMMUNITY AND COMPATIBLE WITH THE MOST WIDELY USED COSMOLOGICAL PARAMETER ESTIMATION CODE. THIS RESEARCH MAKES USE OF DATA FROM THE NASA SATELLITES PLANCK AND LESS DIRECTLY CHANDRA IN ORDER TO CONSTRAIN COSMOLOGY; AND THEREFORE PERFECTLY FITS THE NASA OBJECTIVES AND THE SPECIFICATIONS OF THIS SOLICITATION.