Throughout my life, I have always been taught that gravity is a simple force, however now I struggle to see that being strictly true.
Hence I wanted to ask what modern theoretical physics suggests about this: is gravity the exchange of the theoretical particle graviton or rather a 'bend' in space due to the presence of matter?
I don't need a concrete answer, but rather which side the modern physics and research is leaning to.
Answer
Both.
General relativity describes gravity as curvature of spacetime, and general relativity is an extremely successful theory. Its correct predictions about gravitational waves, as verified directly by LIGO, are especially severe tests.
Gravity also has to be quantum-mechanical, because all the other forces of nature are quantum-mechanical, and when you try to couple a classical (i.e., non-quantum-mechanical) system to a quantum-mechanical one, it doesn't work. See Carlip and Adelman for a discussion of this.
So we know that gravity has to be described both as curvature of spacetime and as the exchange of gravitons. That's not inherently a contradiction. We do similar things with the other forces. We just haven't been able to make it work for gravity.
Carlip, "Is Quantum Gravity Necessary?," http://arxiv.org/abs/0803.3456
Adelman, "The Necessity of Quantizing Gravity," http://arxiv.org/abs/1510.07195
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