Which subject studies the possibility of an afterlife? The answer may be theology and or philosophy. I wish we had a subject that more probabilistically and scientifically studied the possibility of an afterlife.
Stephen David Edwards Dear Doctor and Professor Edwards, Thank you for the suggestion. If you are interested I have written this article that I believe makes parsimonious claims about the afterlife: Book Highly Theoretical Differential Equations of the Afterlife
Theology does more. Recently, there has been quite a lot of crossbreeding in research and knowledge. Philosophy, particularly metaphysics, could touch on the study of the afterlife. Traditionally, however, theology is the main custodian of subjects relating to the afterlife. Securing a perfect afterlife is the ultimate goal of Christians. A section of the major doctrines of Christianity called Eschatology addresses this subject extensively.
Theology plays an important role in the study of afterlife. Jesus said, "Life is in me, and resurreiton is in me." In the New Testament, we can see many paragrphs depicitng the afterlife, especially in the books of gospels and Revelation.
The study of the possibility of an afterlife in Christian theology is often addressed within the broader context of eschatology. Eschatology is a theological sub-discipline that focuses on the study of the "last things," which includes topics such as death, judgment, heaven, hell, and the afterlife.
Within eschatology, Christian scholars and theologians explore various perspectives on what happens to individuals after death. The Christian belief in an afterlife is rooted in key theological concepts found in the Bible, particularly in the New Testament.
The question as to whether an afterlife could possibly exist should be rephrased - so as to obviate from the outset any views and/or arguments that would be informed and cognitively biased by framing the question within the context of ideologies and/or non-objective views and/or 'revealed' yet objectively unproven knowledge (as far as this latter point goes, there are many contradictory "revealed knowledges" out there, and this simple fact alone is enough to objectively invalidate any such approach).
In all matters of fundamental interpretations of reality, the go-to science can only be the science that sits atop the 'Auguste Lecomte' hierarchy of the sciences, just below pure mathematics : to wit, Mathematical Physics - with any results then in need of validation by both theoretical and experimental proofs.
The way to objectively rephrase 'Is an afterlife possible?' is to ask instead 'Can (human) consciousness exist without a material substrate'. Only theoretical physics can possibly provide an answer: In turn, a physics-based rephrasing of this new question is the simple question as to whether consciousness is a fundamental feature of reality, or whether it's derivative aka emergent instead.
There are many very solid physics-based arguments as to why consciousness must be fundamental, and extremely solid arguments why it cannot possibly be emergent.
Therefore, I'd say that the answer to any version of your question is that 'Physics' is the only serious discipline that can tackle the question.
I would suggest the field of "Consciousness Studies", which overlaps with quantum physics, as well as psychology and neurology. This field also includes Near Death Studies and Reincarnation and far too much ignored. It is actually an older field than either Relativity or Quantum Physics, although its name is relatively recent. Some key historical works include "Phantasms of the Living" and one usually abbreviated as "Cross Correspondence" by Saltmarsh. More recently there is "Irreducible Mind" and "Beyond Materialism".
Xerxes D. Arsiwalla, for the mere fact that afterlife is dedicated to a theology, divine and a religion. I think to begin to prove there's an afterlife (even the probabilistic view) one has to start from the basics of
1. Existence of a deity
2. Necessity of an afterlife from the perspective of the assumed-to-be-proved deity.
3. Existence of a Soul. Description of its relationship with the physical body in a measurable way.
Without these two considerations of an afterlife is as close of a guess as considering the Russells teapot.