Jun 01 (Mon)
13:00 MJC_2006 ApplPaul Bushby (Newcastle): The validity of sound-proof approximations for magnetic buoyancy
Magnetic buoyancy plays a key role in the transport of magnetic fields within the solar interior. However, numerical simulations of this process are hampered by the presence of sound waves, which propagate on timescales that are much faster than the timescales of interest for magnetic buoyancy. Several general approaches have been developed to filter out these waves, leading to various "sound-proof" approximations, including the Boussinesq, anelastic and pseudo-incompressible models. I will briefly describe the key assumptions relating to each of these sound-proof approximations, before addressing the question of which of these adequately describe magnetic buoyancy.
Venue: MJC_2006 (Mountjoy Centre)
14:00 MCS0001 PureDon Zagier (MPIM Bonn, ICTP Trieste): Modular forms, mock modular forms, and quantum modular forms
In this series of three talks I want to give an introduction into the wonderful world
of modular forms. These are special functions with huge symmetry groups that are
all-pervasive in modern mathematics and theoretical physics. It has even been
said -- indeed, I may have said it myself -- that "modular forms are everywhere". The
first lecture, on the many connections between modular forms and differential equations,
is meant for a general audience, including applied mathematicians and mathematical
physicists, while the two other talks will introduce more general types of modular
objects that have emerged in recent years in contexts ranging from the string theory
of black holes to the arithmetic properties of quantum invariants of knots. There will
be many examples in all the talks, and no prior knowledge will be assumed.
Venue: MCS0001
Jun 03 (Wed)
14:00 zoom A&CHongji Wei (Harvard): Light Rays as AdS_4 Soft Gluons and Gravitons
Soft symmetries in four-dimensional flat space are generated by infinite-dimensional algebras acting on scattering amplitudes. Using the conformal map between four-dimensional Minkowski space and AdS_4, we show that flat-space leading soft gluon generators map to light transforms of conserved color currents in CFT_3. The three-dimensional conformal descendants of these light-ray operators then generate the full nonabelian soft S-algebra. We similarly identify the light transform of the CFT_3 stress tensor, together with its conformal descendants, as the boundary realization of AdS_4 soft gravitons. Their commutators obey the recently discovered cosmological-constant-deformed \mathcal L_\Lambda w_{1+\infty} algebra, furnishing a universal soft graviton algebra in CFT_3.
Venue: zoom
Online: https://teams.microsoft.com/meet/335604449900654?p=pmuh8mA6eOhnzzNN1h
Click on title to see abstract.
Back to Homepage
Click on series to expand.
Contact: arthur.lipstein@durham.ac.uk
Jun 03 14:00 Hongji Wei (Harvard): Light Rays as AdS_4 Soft Gluons and Gravitons
Soft symmetries in four-dimensional flat space are generated by infinite-dimensional algebras acting on scattering amplitudes. Using the conformal map between four-dimensional Minkowski space and AdS_4, we show that flat-space leading soft gluon generators map to light transforms of conserved color currents in CFT_3. The three-dimensional conformal descendants of these light-ray operators then generate the full nonabelian soft S-algebra. We similarly identify the light transform of the CFT_3 stress tensor, together with its conformal descendants, as the boundary realization of AdS_4 soft gravitons. Their commutators obey the recently discovered cosmological-constant-deformed \mathcal L_\Lambda w_{1+\infty} algebra, furnishing a universal soft graviton algebra in CFT_3.
Venue: zoom
Usual Venue: MCS3070
Contact: andrew.krause@durham.ac.uk
Jun 01 13:00 Paul Bushby (Newcastle): The validity of sound-proof approximations for magnetic buoyancy
Magnetic buoyancy plays a key role in the transport of magnetic fields within the solar interior. However, numerical simulations of this process are hampered by the presence of sound waves, which propagate on timescales that are much faster than the timescales of interest for magnetic buoyancy. Several general approaches have been developed to filter out these waves, leading to various "sound-proof" approximations, including the Boussinesq, anelastic and pseudo-incompressible models. I will briefly describe the key assumptions relating to each of these sound-proof approximations, before addressing the question of which of these adequately describe magnetic buoyancy.
Venue: MJC_2006 (Mountjoy Centre)
Usual Venue: MCS2068
Contact: herbert.gangl@durham.ac.uk
Jun 08 14:00 Don Zagier (MPIM Bonn, ICTP Trieste): Modular forms, mock modular forms, and quantum modular forms
In this series of three talks I want to give an introduction into the wonderful world
of modular forms. These are special functions with huge symmetry groups that are
all-pervasive in modern mathematics and theoretical physics. It has even been
said -- indeed, I may have said it myself -- that "modular forms are everywhere". The
first lecture, on the many connections between modular forms and differential equations,
is meant for a general audience, including applied mathematicians and mathematical
physicists, while the two other talks will introduce more general types of modular
objects that have emerged in recent years in contexts ranging from the string theory
of black holes to the arithmetic properties of quantum invariants of knots. There will
be many examples in all the talks, and no prior knowledge will be assumed.
Venue: MCS0001
Jun 15 14:00 Don Zagier (MPIM Bonn, ICTP Trieste): Modular forms, mock modular forms, and quantum modular forms
In this series of three talks I want to give an introduction into the wonderful world
of modular forms. These are special functions with huge symmetry groups that are
all-pervasive in modern mathematics and theoretical physics. It has even been
said -- indeed, I may have said it myself -- that "modular forms are everywhere". The
first lecture, on the many connections between modular forms and differential equations,
is meant for a general audience, including applied mathematicians and mathematical
physicists, while the two other talks will introduce more general types of modular
objects that have emerged in recent years in contexts ranging from the string theory
of black holes to the arithmetic properties of quantum invariants of knots. There will
be many examples in all the talks, and no prior knowledge will be assumed.
Venue: CLC202
Usual Venue: OC218
Contact: mohamed.anber@durham.ac.uk
For more information, see HERE.
No upcoming seminars have been scheduled (not unusual outside term time).
Usual Venue: MCS3052
Contact: andrew.krause@durham.ac.uk
No upcoming seminars have been scheduled (not unusual outside term time).
Usual Venue: MCS2068
Contact: martin.p.kerin@durham.ac.uk
Jun 11 12:00 Zhang Rongkai (Osaka): Rigidity of the Borell-Brascamp-Lieb inequality
Optimal transport theory has been a powerful tool in
analysis on geometric spaces with curvature bounded since its
introduction into geometric analysis. In this talk, I will first briefly
introduce the application of the optimal transport theory on Riemannian
manifolds and show an interpolation inequality. I will then focus on the
recent work of mine, rigidity on curvature and measure of the
Borell-Brascamp-Lieb inequality on weighted Riemannian manifolds
satisfying the curvature dimension condition. I will also discuss the
Brunn-Minkowski inequality and its rigidity, as well as a few open
questions related.
Venue: MCS2068
Usual Venue: MCS2068
Contact: michael.r.magee@durham.ac.uk
Jun 01 14:00 Don Zagier (MPIM Bonn, ICTP Trieste): Modular forms, mock modular forms, and quantum modular forms
In this series of three talks I want to give an introduction into the wonderful world
of modular forms. These are special functions with huge symmetry groups that are
all-pervasive in modern mathematics and theoretical physics. It has even been
said -- indeed, I may have said it myself -- that "modular forms are everywhere". The
first lecture, on the many connections between modular forms and differential equations,
is meant for a general audience, including applied mathematicians and mathematical
physicists, while the two other talks will introduce more general types of modular
objects that have emerged in recent years in contexts ranging from the string theory
of black holes to the arithmetic properties of quantum invariants of knots. There will
be many examples in all the talks, and no prior knowledge will be assumed.
Venue: MCS0001
Usual Venue: MCS3070
Contact: joe.thomas@durham.ac.uk
No upcoming seminars have been scheduled (not unusual outside term time).
