Maxim Pospelov

Maxim Pospelov
Adjunct Professor of Physics and Astronomy
University of Victoria

PhD (Budker Institute)


Primordial nucleosynthesis and particle physics: I have shown how the long-lived relics, charged under strong or electromagnetic gauge groups, catalyze nuclear by forming bound states with nuclei. In particular, I have shown the possibility for the reduction of 7Li and enhancement of 6Li abundances relative to standard prediction, an intriguing pattern supported by observations. My results have serious implications for the collider searches of supersymmetric particles, where the long-lived charged objects are commonplace occurrence in models with gravitino as the lowest mass SUSY state. I will continue working in this direction as I am motivated by a rather serious discrepancy between the observed and detected lithium abundances.

Secluded models of dark matter. In 2007 Ritz, Voloshin and I pointed out the whole class of WIMP dark matter models that may escape direct detection in underground experiments or at colliders, but have indirect astrophysical signatures. This class of models can accommodate recent "anomalies" in cosmic rays in the 100 GeV domain without fine tuning, as the secluded models often have enhanced annihilation cross sections relative to usual WIMPs. Currently this is one of the most active research areas in astroparticle physics. Possible collider implication of model that we proposed is the sub-GeV vector and scalar resonances that are going to be searched for in the data accumulated by high-luminosity colliders and fixed target experiments. In somewhat related development, my collaborators and I have shown how the B-decays can be used to set stringent constraints on the low mass WIMPs. Overall, the secluded dark matter models together with searches of "dark force" represent a semi-infinite direction in particle physics towards luminosity frontier and I expect to keep active in this field.

B-modes of CMB from new infrared physics. Next five years will be years of active experimental search for the "curl" or B-modes of polarized cosmic microwave background. In 2008, Ritz, Skordis and I have shown that B-mode polarization may result from the inflation-generated fluctuations of the massless pseudoscalar field(s), often predicted by e.g. string theory models. This brings up an important and under-researched question of how to separate the effects of tensor modes, pseudoscalar modes, primordial magnetic field and lensing background, given likely observation of B-modes in the near future. I will continue developing this direction and explore the impact of other IR degrees of freedom on the CMB physics.

Other research directions include new infrared physics models that predict change of masses and couplings it time and space. My idea of environmental dependence of couplings and masses on ambient density stimulated new observational tests within our galaxy. I also study flavor and CP violating effects in new physics models, including supersymmetry. So far my efforts in particle physics were mostly concentrated on searches of new phenomena related to non-SM physics. This is "high-risk/high-gain" program, and in the future I will try to develop some more balanced approach and add some "standard physics" directions in my research. What precisely it is going to be remains to be seen...

Research interests

  • Theoretical particle physics
  • David McKeen, Maxim Pospelov, Muon Capture Constraints on Sterile Neutrino Properties, Phys.Rev.D82:113018,2010, arxiv: 1011.3046
  • Maxim Pospelov, Josef Pradler, Big Bang Nucleosynthesis as a Probe of New Physics, Ann.Rev.Nucl.Part.Sci.60:539-568,2010, arxiv: 1011.1054
  • Jonathan M. Arnold, Maxim Pospelov, Michael Trott, Mark B. Wise, Scalar Representations and Minimal Flavor Violation, JHEP 1009:073,2010, arxiv: 0911.2225
  • Brian Batell, Maxim Pospelov, Adam Ritz, Direct Detection of Multi-component Secluded WIMPs, Phys.Rev.D79:115019,2009, arxiv: 0903.3396
  • Maxim Pospelov, Adam Ritz, Astrophysical Signatures of Secluded Dark Matter, Phys.Lett.B671:391-397,2009, arxiv: 0810.1502
  • Maxim Pospelov, Adam Ritz, Constantinos Skordis, Pseudoscalar perturbations and polarization of the cosmic microwave background, Phys.Rev.Lett.103:051302,2009, arxiv: 0808.0673
  • Maxim Pospelov, Josef Pradler, Frank Daniel Steffen, Constraints on Supersymmetric Models from Catalytic Primordial Nucleosynthesis of Beryllium, JCAP 0811:020,2008, arxiv: 0807.4287
  • Maxim Pospelov, Adam Ritz, Mikhail B. Voloshin, Bosonic super-WIMPs as keV-scale dark matter, Phys.Rev.D78:115012,2008, arxiv: 0807.3279
  • Pavel A. Bolokhov, Maxim Pospelov, Low-energy constraints on kappa-Minkowski extension of the Standard Model, Phys.Lett.B677:160-163,2009, arxiv: 0807.1522
  • Maxim Pospelov, Adam Ritz, Resonant scattering and recombination of pseudo-degenerate WIMPs, Phys.Rev.D78:055003,2008, arxiv: 0803.2251
  • M. Raidal, A. van der Schaaf, I. Bigi, M.L. Mangano, Y. Semertzidis, S. Abel, S. Albino, S. Antusch, E. Arganda, B. Bajc, S. Banerjee, C. Biggio, M. Blanke, W. Bonivento, G.C. Branco, D. Bryman, A.J. Buras, L. Calibbi, A. Ceccucci, P.H. Chankowski, S. Davidson, A. Deandrea, D.P. DeMille, F. Deppisch, M. Diaz, B. Duling, M. Felcini, W. Fetscher, D.K. Ghosh, M. Giffels, G. Giudice, E. Goudzovskij, T. Han, P.G. Harris, M.J. Herrero, J. Hisano, R.J. Holt, K. Huitu, A. Ibarra, O. Igonkina, A. Ilakovac, J. Imazato, G. Isidori, F.R. Joaquim, M. Kadastik, Y. Kajiyama, S.F. King, K. Kirch, M.G. Kozlov, M. Krawczyk, T. Kress, O. Lebedev, A. Lusiani, E. Ma, G. Marchiori, I. Masina, G. Moreau, T. Mori, M. Muntel, F. Nesti, C.J.G. Onderwater, P. Paradisi, S.T. Petcov, M. Picariello, V. Porretti, A. Poschenrieder, M. Pospelov, L. Rebane, M.N. Rebelo, A. Ritz, L. Roberts, A. Romanino, A. Rossi, R. Rueckl, G. Senjanovic, N. Serra, T. Shindou, Y. Takanishi, C. Tarantino, A.M. Teixeira, E. Torrente-Lujan, K.J. Turzynski, T.E.J. Underwood, S.K. Vempati, O. Vives, Flavour physics of leptons and dipole moments, Eur.Phys.J.C57:13-182,2008, arxiv: 0801.1826
  • Maxim Pospelov, Adam Ritz, Mikhail B. Voloshin, Secluded WIMP Dark Matter, Phys.Lett.B662:53-61,2008, arxiv: 0711.4866
  • Keith A. Olive, Maxim Pospelov, Environmental Dependence of Masses and Coupling Constants, Phys.Rev.D77:043524,2008, arxiv: 0709.3825
  • Pavel A. Bolokhov, Maxim Pospelov, Classification of Dimension 5 Lorentz Violating Interactions in the Standard Model, Phys.Rev.D77:025022,2008, arxiv: hep-ph/0703291
  • Chris Bird, Kristen Koopmans, Maxim Pospelov, Primordial Lithium Abundance in Catalyzed Big Bang Nucleosynthesis, Phys.Rev.D78:083010,2008, arxiv: hep-ph/0703096
  • Pavel A. Bolokhov, Maxim Pospelov, CPT-odd Leptogenesis, Phys.Rev.D74:123517,2006, arxiv: hep-ph/0610070
  • Stephan J. Huber, Maxim Pospelov, Adam Ritz, Electric dipole moment constraints on minimal electroweak baryogenesis, Phys.Rev.D75:036006,2007, arxiv: hep-ph/0610003
  • Pavel Bolokhov, Maxim Pospelov, Michael Romalis, Electric Dipole Moments as Probes of CPT Invariance, Phys.Rev.D78:057702,2008, arxiv: hep-ph/0609153
  • Maxim Pospelov, Adam Ritz, Yudi Santoso, Sensitivity to new supersymmetric thresholds through flavour and CP violating physics, Phys.Rev.D74:075006,2006,arxiv: hep-ph/0608269
  • Maxim Pospelov, Particle physics catalysis of thermal Big Bang Nucleosynthesis, Phys.Rev.Lett.98:231301,2007, arxiv: hep-ph/0605215
  • C. Bird, R. Kowalewski, M. Pospelov, Dark matter pair-production in b -> s transitions, Mod.Phys.Lett. A21 (2006) 457-478, arxiv: hep-ph/0601090
  • Maxim Pospelov, Adam Ritz, Yudi Santoso, Flavor and CP violating physics from new supersymmetric thresholds, Phys.Rev.Lett. 96 (2006) 091801, arxiv: hep-ph/0510254
  • Keith A. Olive, Maxim Pospelov, Adam Ritz, Yudi Santoso, CP-odd Phase Correlations and Electric Dipole Moments, Phys.Rev. D72 (2005) 075001, arxiv: hep-ph/0506106
  • Pavel A. Bolokhov, Stefan Groot Nibbelink, Maxim Pospelov, Lorentz Violating Supersymmetric Quantum Electrodynamics, Phys.Rev. D72 (2005) 015013, arxiv: hep-ph/0505029
  • Maxim Pospelov, Adam Ritz, Electric dipole moments as probes of new physics, Annals Phys. 318 (2005) 119-169, arxiv: hep-ph/0504231
  • John Paul Archambault, Andrzej Czarnecki, Maxim Pospelov, Electric Dipole Moments of Leptons in the Presence of Majorana Neutrinos, Phys.Rev. D70 (2004) 073006, arxiv: hep-ph/0406089
  • Seokcheon Lee, Keith A. Olive, Maxim Pospelov, Quintessence Models and the Cosmological Evolution of alpha, Phys.Rev. D70 (2004) 083503, arxiv: astro-ph/0406039
  • Stefan Groot Nibbelink, Maxim Pospelov, Lorentz Violation in Supersymmetric Field Theories, Phys.Rev.Lett. 94 (2005) 081601, arxiv: hep-ph/0404271
  • Charles Picciotto, Maxim Pospelov, Unstable Relics as a Source of Galactic Positrons, Phys.Lett. B605 (2005) 15-25, arxiv: hep-ph/0402178
  • Robert C. Myers, Maxim Pospelov, Ultraviolet modifications of dispersion relations in effective field theory, Phys.Rev.Lett. 90 (2003) 211601, arxiv: hep-ph/0301124
  • C.P. Burgess, M. Pospelov, T. ter Veldhuis, The Minimal Model of Nonbaryonic Dark Matter: A Singlet Scalar, Nucl.Phys.B619:709-728,2001, arxiv: hep-ph/0011335
  • C.P. Burgess (McGill University), J. Matias (IFAE, U. Aut. Barcelona), M. Pospelov (U. Minnesota), A Higgs or Not a Higgs? What to Do if You Discover a New Scalar Particle, Int.J.Mod.Phys. A17 (2002) 1841-1918, arxiv: hep-ph/9912459
  • Observing a light dark matter beam with neutrino experiments, Patrick deNiverville, Maxim Pospelov, Adam Ritz, arxiv: 1107.4580
  • Neutrino Physics with Dark Matter Experiments and the Signature of New Baryonic Neutral Currents, Maxim Pospelov, arxiv:hep-ph/arxiv: 1103
  • New Parity-Violating Muonic Forces, Brian Batell, David McKeen, Maxim Pospelov,arxiv: 1103.0721
  • On Lorentz violation in Horava-Lifshitz type theories, Maxim Pospelov, Yanwen Shang, arxiv: 1010.5249
  • Axio-electric effect, A. Derevianko, V. A. Dzuba, V. V. Flambaum, M. Pospelov,arxiv: 1007.1833
  • Metastable GeV-scale particles as a solution to the cosmological lithium problem, Maxim Pospelov, Josef Pradler, arxiv: 1006.4172
  • Bs Mixing and Electric Dipole Moments in MFV, Brian Batell, Maxim Pospelov,arxiv: 1006.2127
  • Sub-eV scalar dark matter through the super-renormalizable Higgs portal, Federico Piazza, Maxim Pospelov, arxiv: 1003.2313
  • Atomic Ionization by keV-scale Pseudoscalar Dark Matter Particles, V. A. Dzuba, V. V. Flambaum, M. Pospelov, arxiv: 1002.2979
  • Multi-lepton Signatures of a Hidden Sector in Rare B Decays, Brian Batell, Maxim Pospelov, Adam Ritz, arxiv: 0911.4938
  • Solar Gamma Rays Powered by Secluded Dark Matter, Brian Batell, Maxim Pospelov, Adam Ritz, Yanwen Shang, arxiv: 0910.1567
  • Exploring Portals to a Hidden Sector Through Fixed Targets, Brian Batell, Maxim Pospelov, Adam Ritz, arxiv: 0906.5614
  • Resonant enhancement of nuclear reactions as a possible solution to the cosmological lithium problem, Richard H. Cyburt, Maxim Pospelov, arxiv: 0906.4373
  • Big Bang Nucleosynthesis and Particle Dark Matter, Karsten Jedamzik, Maxim Pospelov, arxiv: 0906.2087
  • Scalar-tensor theories with pseudoscalar couplings, Victor Flambaum, Simon Lambert, Maxim Pospelov, arxiv: 0902.3217
  • Secluded U(1) below the weak scale, Maxim Pospelov, arxiv: 0811.1030
  • Bridging the primordial A=8 divide with Catalyzed Big Bang Nucleosynthesis, Maxim Pospelov, arxiv: 0712.0647
  • The galactic 511 keV line from electroweak scale WIMPs, Maxim Pospelov, Adam Ritz, arxiv: hep-ph/0703128
  • Ghosts and Tachyons in the Fifth Dimension, Maxim Pospelov, arxiv: hep-ph/0412280
  • Experimental Challenges for Quantum Gravity, Robert C. Myers, Maxim Pospelov,arxiv: gr-qc/0402028
Current graduate students
  • Anthony Fradette (MSc)
  • Jonathan Sharman (PhD)
Graduated students (UVic)
  • Pavel Bolokhov (PhD, 2007)
  • Chris Bird (PhD, 2008)
  • Kristen Koopmans (MSc, 2007)
  • Simon Lambert (MSc, 2008)
Current postdoctoral researchers
  • Kristan Jensen
  • David McKeen
  • John Ward
  • Touko Tahkokallio
  • Yudi Santoso
  • Stefan Groot Nibbelink