Multi-messenger astrophysics — the study of astrophysical events observed simultaneously through multiple cosmic messengers: electro-magnetic radiation (γ / X / UV / visible / IR / radio), gravitational waves, neutrinos, and…
multi-messenger-astrophysics
Chirp mass: M_c = (m1·m2)^(3/5) / (m1+m2)^(1/5)
The chirp mass M_c = (m_1·m_2)^(3/5)/(m_1+m_2)^(1/5) is the combination of component masses that controls the leading-order post-Newtonian…
GW-EM delay: Δt = d·(1/v_gw - 1/c)
For a multi-messenger event at luminosity distance d producing both gravitational-wave and electromagnetic signals emitted simultaneously…
Inspiral frequency evolution: f(t) ∝ (t_c − t)^(-3/8)
The leading-order (Newtonian / quadrupole-radiation) post-Newtonian expansion of a compact binary's gravitational-wave frequency evolution…
Chirp-mass equal-mass: M_c(m_1=m_2=m) = 2^(4/5)·m/2
Sympy-exact witness of the equal-mass chirp-mass reduction. Setup: M_c = (m_1·m_2)^(3/5) / (m_1+m_2)^(1/5). Identity: substituting m_1 =…
GW-EM simultaneity: Δt(v_gw=c) = 0
Sympy-exact witness of the GW-EM arrival-time coincidence in the v_gw = c limit. Setup: Δt = d·(1/v_gw − 1/c) as a three-symbol function. …
Inspiral-frequency ratio: f(t_c/2)/f(0) = 2^(3/8)
Sympy-exact witness of the inspiral-frequency halving-time ratio. Setup: f(t) ∝ (t_c − t)^(-3/8) — the quadrupole-radiation-back-reaction…
GW chirp mass M_chirp = (m_1 m_2)^{3/5}/(m_1+m_2)^{1/5}; Holder/Minkowski moments
Gravitational-wave chirp mass framework (Peters-Mathews 1963 Phys Rev 131, 435; Peters 1964 Phys Rev 136, B1224). Setup: for an inspiraling…
Standard-siren Hubble: H_0 = c z/d_L (low-z limit); luminosity distance via metric
Standard-siren Hubble-constant framework (Schutz 1986 Nature 323, 310). Setup: GW inspirals are 'self-calibrating' distance probes - the…
Multi-messenger achromaticity: Delta t = D(1/v_GW - 1/c) = 0 at v_GW = c (Hasse-Minkowski)
Multi-messenger achromaticity framework (Will 1998 Phys Rev D 57, 2061; LIGO-Virgo + GRB 170817 collaboration 2017 ApJL 848, L13). Setup:…
Theorem: M_chirp * 2^{1/5} - m = 0 at m_1 = m_2 = m (equal-mass chirp-mass identity)
Theorem (chirp-mass-equal-mass canonical): for m_1 = m_2 = m, M_chirp = (m m)^{3/5}/(2m)^{1/5} = m^{6/5}/(2 m)^{1/5} = m^{6/5}/(2^{1/5}…
Theorem: H_0 d_L - c z = 0 (standard-siren Hubble identity at low z)
Theorem (standard-siren-Hubble canonical): H_0 = c z/d_L cleared gives H_0 d_L = c z, residual H_0 d_L - c z = 0 identically. Canonical…
Theorem: Delta t at v_GW = c equals 0 (GW170817 multi-messenger achromaticity)
Theorem (achromaticity-vGW-c canonical): substituting v_GW = c into Delta t = D(1/v_GW - 1/c) gives D(1/c - 1/c) = 0 identically. Canonical…
Gravitational wave detection (LIGO 2015)
Abbott et al 2016 (LIGO-Virgo) GW150914 first direct detection; binary-black-hole merger 36+29 -> 62 Msun; Nobel 2017; opens GW astronomy.
Neutrino astronomy (IceCube)
IceCube 2013 detection of >100 TeV astrophysical neutrinos; 2018 TXS 0506+056 association with high-energy gamma-ray blazar;…
Kilonova GW170817 (binary neutron star)
GW170817 + GRB 170817A + AT2017gfo (Aug 2017): first BNS merger seen in GW + gamma-rays + optical/IR/UV/X-ray; r-process heavy-element…
UHECR detection (Pierre Auger)
Pierre Auger Observatory 2003+: detection of >10^18 eV cosmic-rays via giant air-showers; spectrum cutoff at GZK (Greisen-Zatsepin-Kuzmin)…
Fast radio bursts (FRB)
Lorimer-Bailes 2007 + CHIME 2018+: millisecond ~Jy radio bursts at z~0.1-1; magnetar-engine model for repeaters; FRB 200428 from SGR…
Dark matter direct detection (XENON)
XENONnT 2023 limits on WIMP-nucleon cross-section sigma_SI < 2.6 x 10^-47 cm^2 at 30 GeV/c^2; LUX-ZEPLIN + DARWIN successors; null results…
GW170817 (2017)
LIGO-Virgo + 70+ obs 2017 binary-neutron-star + kilonova; modern modern foundational + r-process-confirmation + standard-siren H0…
GW150914 (2015)
LIGO 2015 first GW-direct-detection + 2017 Nobel Weiss-Barish-Thorne; modern modern foundational + GW190521 + 2024 O4 100+ events catalog.
PTA nHz (NANOGrav 2023)
NANOGrav-EPTA-PPTA-CPTA 2023 nHz stochastic-GW background; modern modern foundational text + 2024 IPTA combined + binary-SMBH expected.
Kilonova (2017)
B Metzger 2010 + GW170817 confirm 2017; modern modern foundational text + r-process Au + Pt heavy-element nucleosynthesis kilonova-Lα.
TXS 0506 (IceCube 2018)
IceCube 2018 TXS 0506+056 high-energy-neutrino blazar-source; modern modern foundational + multi-wavelength + 2024 ngT activity-flare…
Primordial GW (BICEP/Keck)
BICEP2 2014 + BICEP/Keck 2021 r<0.036 limit primordial-GW; modern modern foundational + LiteBIRD + Simons-Observatory CMB-S4 future.