Gravitons are hypothetical particles that are postulated in some theories, such as quantum gravity, to mediate the force of gravity. the nature and properties of gravitons are still not well-understood and remain purely theoretical. Therefore, the question of whether gravitons have mass or not is still a topic of active research and debate among physicists.
In general, massless particles, such as photons (particles of light), are often described as being mediators of forces. However, whether gravitons, if they exist, would be massless or possess a small mass is uncertain and depends on the specific theoretical framework being considered. Some theories suggest that gravitons are massless, similar to photons, while others propose that they could have a non-zero mass.
It's important to note that as scientific understanding advances, new discoveries and theories may emerge that could provide further insights into the properties of gravitons. Therefore, the current understanding regarding the mass of gravitons might have evolved. It's always a good idea to consult the latest scientific literature or consult with experts in the field for the most up-to-date information.