Are physics and natural sciences considered liberal arts? I was surprised to see the description given for "liberal arts education" in Wikipedia as follows:


  Liberal arts today consists of four types of areas: the natural sciences, social sciences, arts, and humanities. Its central academic disciplines are physics, biology, philosophy, logic, linguistics, literature, history, political science, psychology, mathematics, and many others.
  Liberal arts education (Wikipedia article) 


I'm obviously talking about the modern usage of "liberal arts", not the ancient or historical term (trivium and quadrivium). I had in mind something more akin to humanities, so excluding natural sciences like physics, chemistry, even astronomy. My conception seems to be right at least by some definitions of the term. The first result I get when I search for "liberal arts" is a definition by Oxford Dictionaries:


  North American
  Arts subjects such as literature and history, as distinct from science and technology.
  Oxford Dictionaries at lexico.com


It's defined by Collins as:


  (Education) the fine arts, humanities, sociology, languages, and literature. Often shortened to: arts 
  Collins English Dictionary


It's possible that the British English definition and/or the meaning of the term outside North America or USA is different. Two of the most common online American dictionaries seem to emphasize "general knowledge" as opposed to professional knowledge:


  2 : college or university studies (such as language, philosophy, literature, abstract science) intended to provide chiefly general knowledge and to develop general intellectual capacities (such as reason and judgment) as opposed to professional or vocational skills
  Merriam-Webster
  
  pl.n.
  1. Academic disciplines, including literature, history, languages, philosophy, mathematics, and general sciences, viewed in contrast to professional and technical disciplines.
  American Heritage Dictionary


I'm not sure whether things like physics and chemistry fall within the American dictionary definitions above, but the Wikipedia article clearly says that the natural sciences and life sciences are part of the liberal arts, and gives examples of physics, chemistry, geology, biology and neuroscience. 
Liberal arts education: Modern usage (Wikipedia article)

Notwithstanding that many American dictionaries don't mention the natural sciences by name, at least the one below does:


  n.pl.
  1. academic college courses providing general knowledge and comprising the arts, humanities, natural sciences, and social sciences. 
  Random House Kerneman Webster's College Dictionary


Does anyone know whether even in America there's consensus among academics and institutions that "liberal arts" include things like physics, chemistry, geology or neuroscience?
There is little consensus, I think. But mostly it is a matter of convenience and organization at colleges and universities. I studied mathematics. I earned both a BA and an MA at different places, one of them an R1 university. Just by asking, the degrees could have been designated BS and MS. Other places the math department is in the School of Engineering. But that is just an organizational convenience, though it might let some departments share faculty more easily when it comes to budgets and such. Some places CS is part of the math department and is a "liberal art". Other places it is part of an engineering discipline. Still other places it is different from both. 

But in the US, at a liberal arts college, the student is expected to gain a broad and well rounded education. It will include both literature and science, even though it might focus somewhat on a single area. 

But, your question, itself, details that there is no consensus on this.