Tuesday, September 3, 2024

Primordial Black Holes with Elba Alonso-Monsalve and David Kaiser

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Recorded: 2024/07/03 Released: 2024/09/03

Jim talks with Elba Alonso-Monsalve and David Kaiser about the prospects of a class of primordial black holes as a candidate for dark matter. These tiny black holes form just after the inflationary epoch when it is possible for them to form from inhomogeneities wihtout a prior history as a star. Black holes forming during this time time-frame would not have to be color neutral as baryons and mesons are.
------------------------------------------- Notes:

1. The articles that we discussed for this program:
2. Other papers and articles mentioned in the podcast: 3.Dave's webpage at MIT. 4. Related Episodes of Physics Frontiers:
5. Please visit and comment on our subreddit, YouTube Channel, or Twitter account. These are also places to look for announcements of new episodes and the like. And if you could help us keep this going by contributing to our Patreon, we'd be grateful.
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Friday, May 31, 2024

Quantum Machine Learning with Bruna Shinohara

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Recorded: 2024/02/16 Released: 2024/05/31

Jim talks with Bruna Shinohara about quantum machine learning.
------------------------------------------- Notes:

1. The article that we discussed in this program:
2. Other papers and articles mentioned in the podcast:
  • Aaronson, Scott, "Read the Fine Print." Nature Physics 11 211 (2015). [ Free
  • I'll ask Bruna to send me a link to the large QML article she talked about in the podcast.
/ 3. Related Episodes of Physics Frontiers:
4. Please visit and comment on our subreddit, YouTube Channel, or Twitter account. These are also places to look for announcements of new episodes and the like. And if you could help us keep this going by contributing to our Patreon, we'd be grateful.
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Sunday, March 31, 2024

Maxwellian Ratchets with Alex Jurgens

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Recorded: 2023/12/18 Released: 2024/03/31

Jim talks with Alex Jurgens of INRIA about Maxwellian Ratchets. These are abstract machines that react to outside stimuli, These are highly specified theoretical realizations of Maxwell's Demon, who flaunts the second law of thermodynamics. Jurgens discusses these in terms of entropy, information processessing, and the second law.
------------------------------------------- Notes:

1. The article that we discussed in this program:
2. Related Episodes of Physics Frontiers:
3. Books mentioned:

Sunday, January 28, 2024

Undecidability and Theories of Everything with Claus Kiefer

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Recorded: 2023/08/07 Released: 2024/01/28

Jim talks with Claus Kiefer about his recent essay on the relationship between the Gödel's incompleteness theoerems and the possibility of developing a theory of everything. Incompleteness was originally developed to show that every axiomatic system that is sufficiently robust admits well-formed statements that have a liar's paradox-like structure - if you assume the statement is true, you can prove it's false, and vice-versa. This statement is then said to be undecidable. Undecidability also famously comes up in the halting problem of computer science and the continuum hypothesis. Professor Kiefer speculates here that theories of everything are similarly undecidable.
------------------------------------------- Notes:

1. The article that we discussed in this program:
  • Kiefer, Claus, "Gödel's undecidability theorems and the search for a theory of everything" (2023) [arXiv]
2. Other papers referred to in this podcast:
  • Cubitt, T.,D. Perez-Garcia and H.M. Wolf, "Undecidability of the Spectral Gap." Nature 528 207 (2015) [arXiv]
  • Goedel,, K., "On Formally Undecidable Propositions of Principia Mathematica and Related Systems." Monatshefte für Mathematik und Physik 38 173 (1931) [Free]
    • The Undecidable [Amazon], M. Davis, ed. Reprints Goedel's paper and other work from the 1930's. Dover book.
3. Related Episodes of Physics Frontiers:
4. Books mentioned:
5. Please visit and comment on our subreddit, YouTube Channel, or Twitter account. These are also places to look for announcements of new episodes and the like. And if you could help us keep this going by contributing to our Patreon, we'd be grateful.
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Sunday, August 20, 2023

The Measurement Problem with Nick Ormrod and V. Vilasini

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Recorded: 2023/07/17 Released: 2023/08/20

Jim talks with Nick Ormrod and V. Vilasini about their use of categorical probability theory to study the measurement problem of quantum mechanics. They use the CPT to analyze a no-go theorem to see where there are weaknesses in the underlying structure of quantum mechanics without referring to particular mathematical formualtions of the subject, allowing them to show that the measurement problem comes from difficulties in our understanding of the evolution of quantum states or the way we interpret measurements.
------------------------------------------- Notes:

1. The article that we discussed in this program:
  • Ormrod, N., V. Vilasini, and J. Barrett, "Which Theories Have a Measurement Problem?" (2023) [arXiv]
2. Other papers referred to in this podcast:
  • N. Ormrod and J. Barrett, "A No-Go Theorem for Absolute Observed Events Without Inequalities or Modal Logic." [arXiv]
  • V. Vilasini and M. P. Woods, "A General Framework for Consistent Logical Reasoning in Wigner's Friend Scenarios: Subjective Perspectives of Agents Within a Single Quantum Circuit." [arXiv]
  • Maudlin, T., "Three Measurement Problems." Topoi 14 7 (1995).
3. Related Episodes of Physics Frontiers:
4. Please visit and comment on our subreddit, YouTube Channel, or Twitter account. These are also places to look for announcements of new episodes and the like. And if you could help us keep this going by contributing to our Patreon, we'd be grateful.
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Sunday, July 9, 2023

Stochastic Thermodynamics with David Wolpert

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Recorded: 2023/05/10 Released: 2023/07/09

Jim talks with David Wolpert about the stochastic thermodynamics of compuation. The discussion focuses on recent developments in the relationship between non-equilibrium processes and information processing, having deep implications on how we view the world and how we apply statistical physics to biological, computational, and other systems.
------------------------------------------- Notes:

1. The articles that we discussed in this program:
2. Other papers referred to in this podcast:

Sunday, June 18, 2023

Quantum Money with Jiahui Liu

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Recorded: 2023/03/28 Released: 2023/06/18

Jim talks with Jiahui Liu about quantum money. Quantum Money is a key milestone in quantum crytography -- not for the breaking of codes (e.g., Shor's algothrithm), but instead for using quantum computing to improve cryptography beyond what is possible in classical cryptography. The difficulty is, however, a fully satisfactory way to implement quantum money is not currently known. Jiahui discusses both how to show that a possible implementation doesn't work, and how she developed another scheme to implemet quantum money. She also discusses the history of quantum money and some of the things quantum crytographers can do once they have a reliable quantum money scheme.
------------------------------------------- Notes:

1. The articles that we discussed in this program:
2. Related Episodes of Physics Frontiers:
3. Please visit and comment on our subreddit, YouTube Channel, or Twitter account. These are also places to look for announcements of new episodes and the like. And if you could help us keep this going by contributing to our Patreon, we'd be grateful.
← Previous ( Born Rule and Gravity ) ( Stochastic Thermodynamics ) Next →