Hardy's setup and elements of reality

✍ Scribed by Louis Marchildon

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 137 KB
• Volume: 42
• Category: Article
• ISSN: 1386-9477
• DOI: 10.1016/j.physe.2009.06.070

✦ Synopsis

Several arguments have been proposed some years ago, attempting to prove the impossibility of defining Lorentz-invariant elements of reality. Here I revisit that question, and bring a number of additional considerations to it. I will first analyze Hardy's argument, which was meant to show that Lorentz-invariant elements of reality are indeed inconsistent with quantum mechanics. I will then investigate to what extent the light cone associated with an event can be used to define Lorentzinvariant elements of reality. It turns out to be possible, but elements of reality associated with a product of two commuting operators will not always be equal to the product of elements of reality associated with each operator. I will finally examine a number of ways in which the paradoxical features of Hardy's experiment can be better understood.