Raphael Bousso () (born 1971) is a

theoretical physicist Theoretical physics is a branch of physics that employs mathematical models and abstractions of physical objects and systems to rationalize, explain and predict natural phenomena. This is in contrast to experimental physics, which uses experime ...

and

cosmologist Cosmology () is a branch of physics and metaphysics dealing with the nature of the universe. The term ''cosmology'' was first used in English in 1656 in Thomas Blount's ''Glossographia'', and in 1731 taken up in Latin by German philosopher ...

. He is a professor at the Berkeley Center for Theoretical Physics in the Department of Physics,

UC Berkeley The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California) is a public land-grant research university in Berkeley, California. Established in 1868 as the University of California, it is the state's first land-grant uni ...

. He is known for the Bousso bound on the information content of the universe. With

Joseph Polchinski Joseph Gerard Polchinski Jr. (; May 16, 1954 – February 2, 2018) was an American theoretical physicist and string theorist. Biography Polchinski was born in White Plains, New York, the elder of two children to Joseph Gerard Polchinski Sr. (1929 ...

, Bousso proposed the

string theory landscape The string theory landscape or landscape of vacua refers to the collection of possible false vacua in string theory,The number of metastable vacua is not known exactly, but commonly quoted estimates are of the order 10500. See M. Douglas, "The ...

as a solution to the

cosmological constant problem In cosmology, the cosmological constant problem or vacuum catastrophe is the disagreement between the observed values of vacuum energy density (the small value of the cosmological constant) and theoretical large value of zero-point energy sugges ...

Life and career

Bousso was born in

Haifa Haifa ( he, חֵיפָה ' ; ar, حَيْفَا ') is the third-largest city in Israel—after Jerusalem and Tel Aviv—with a population of in . The city of Haifa forms part of the Haifa metropolitan area, the third-most populous metropol ...

, Israel, the son of late scientis
Dino Bousso
He grew up near

Augsburg Augsburg (; bar , Augschburg , links=https://en.wikipedia.org/wiki/Swabian_German , label=Swabian German, , ) is a city in Swabia, Bavaria, Germany, around west of Bavarian capital Munich. It is a university town and regional seat of the ...

, Germany, where he studied physics from 1990 until 1993. Bousso earned his

Ph.D. A Doctor of Philosophy (PhD, Ph.D., or DPhil; Latin: or ') is the most common degree at the highest academic level awarded following a course of study. PhDs are awarded for programs across the whole breadth of academic fields. Because it is ...

Cambridge University The University of Cambridge is a Public university, public collegiate university, collegiate research university in Cambridge, England. Founded in 1209 and granted a royal charter by Henry III of England, Henry III in 1231, Cambridge is the world' ...

in 1997; his doctoral advisor was Stephen Hawking. Bousso did

postdoctoral research A postdoctoral fellow, postdoctoral researcher, or simply postdoc, is a person professionally conducting research after the completion of their doctoral studies (typically a PhD). The ultimate goal of a postdoctoral research position is to pu ...

at Stanford University until 2000, and at the

Kavli Institute for Theoretical Physics The Kavli Institute for Theoretical Physics (KITP) is a research institute of the University of California, Santa Barbara. KITP is one of the most renowned institutes for theoretical physics in the world, and brings theorists in physics and rela ...

in Santa Barbara until 2002. In 2002/03, Bousso was a fellow at the

Harvard University Harvard University is a private Ivy League research university in Cambridge, Massachusetts. Founded in 1636 as Harvard College and named for its first benefactor, the Puritan clergyman John Harvard, it is the oldest institution of high ...

physics department and the

Radcliffe Institute for Advanced Study The Radcliffe Institute for Advanced Study at Harvard University—also known as the Harvard Radcliffe Institute—is a part of Harvard University that fosters interdisciplinary research across the humanities, sciences, social sciences, arts, a ...

. Since 2002, he has been a professor in the physics department at the

University of California, Berkeley The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California) is a public land-grant research university in Berkeley, California. Established in 1868 as the University of California, it is the state's first land-grant u ...

. In 2012, Bousso was elected Fellow of the American Physical Society "for fundamental discoveries in the field of quantum cosmology, including the covariant entropy bound and the string landscape."

Research

Bousso's research is focused on quantum gravity and

cosmology Cosmology () is a branch of physics and metaphysics dealing with the nature of the universe. The term ''cosmology'' was first used in English in 1656 in Thomas Blount's ''Glossographia'', and in 1731 taken up in Latin by German philosopher ...

, particularly through the study of

quantum information Quantum information is the information of the state of a quantum system. It is the basic entity of study in quantum information theory, and can be manipulated using quantum information processing techniques. Quantum information refers to both t ...

. His 1999 covariant entropy bound ( Bousso bound) established a general relation between quantum information and the geometry of spacetime (i.e.,

gravity In physics, gravity () is a fundamental interaction which causes mutual attraction between all things with mass or energy. Gravity is, by far, the weakest of the four fundamental interactions, approximately 1038 times weaker than the stro ...

). The Bousso bound has since been refined and strengthened, leading to provable new results in quantum field theory, such as the quantum null energy condition. Bousso has also worked on the

black hole information paradox The black hole information paradox is a puzzle that appears when the predictions of quantum mechanics and general relativity are combined. The theory of general relativity predicts the existence of black holes that are regions of spacetime from wh ...

(firewall problem). Since 2018, he has led a consortium of theoretical and experimental physicists exploring and developing the relations between quantum gravity, quantum information, and quantum computing. In 2000, Bousso and

argued that string theory has many long-lived vacua, including solutions compatible with the observed positive value of the

cosmological constant In cosmology, the cosmological constant (usually denoted by the Greek capital letter lambda: ), alternatively called Einstein's cosmological constant, is the constant coefficient of a term that Albert Einstein temporarily added to his field eq ...

(

vacuum energy Vacuum energy is an underlying background energy that exists in space throughout the entire Universe. The vacuum energy is a special case of zero-point energy that relates to the quantum vacuum. The effects of vacuum energy can be experiment ...

). This came to be called the "landscape of string theory." Bousso has developed an approach to the cosmological measure problem, with the ultimate goal of testing the string theory landscape.

Life and career

Research

References

External links