Dmitri Martila

[112] viXra:2511.0136 submitted on 2025-11-26 11:16:02 , (411 unique-IP downloads)

Riemann Hypothesis Via Wang's Peer-Reviewed Paper

Authors: Dmitri Martila
Category: Number Theory

[111] viXra:2509.0102 submitted on 2025-09-17 14:24:04 , (309 unique-IP downloads)

First Chebyshev Function is Key to Riemann Hypothesis

Authors: Dmitri Martila
Category: Number Theory

[110] viXra:2411.0036 submitted on 2024-11-05 16:36:03 , (167 unique-IP downloads)

On the Nicolas Criterion for Riemann Hypothesis

Authors: Dmitri Martila, Stefan Groote
Category: Number Theory

[109] viXra:2408.0024 submitted on 2024-08-06 20:41:28 , (148 unique-IP downloads)

The Nicolas Criterion for a Proof of the Riemann Hypothesis

Authors: Dmitri Martila, Stefan Groote
Category: Number Theory

[108] viXra:2407.0018 submitted on 2024-07-03 20:04:33 , (272 unique-IP downloads)

Riemann Hypothesis Via Nicolas Criterion

Authors: Dmitri Martila
Category: Number Theory

[107] viXra:2406.0150 submitted on 2024-06-25 13:30:58 , (336 unique-IP downloads)

Simple Symmetry Proves All Three Riemann's Hypotheses

Authors: Dmitri Martila
Category: Number Theory

[106] viXra:2406.0033 replaced on 2024-06-13 12:34:02 , (476 unique-IP downloads)

Explanations of the Riemann Hypothesis

Authors: Dmitri Martila
Category: Condensed Matter

[105] viXra:2402.0098 replaced on 2024-03-27 19:36:33 , (369 unique-IP downloads)

On Navier-Stokes Equations

Authors: Dmitri Martila
Category: Functions and Analysis

[104] viXra:2402.0097 submitted on 2024-02-18 20:09:49 , (198 unique-IP downloads)

Riemann Hypothesis is [Claimed to Be] Proven

Authors: Dmitri Martila
Category: Number Theory

[103] viXra:2402.0096 submitted on 2024-02-18 20:06:49 , (189 unique-IP downloads)

Proof for Localized Energy or Inertia in Curved Spacetime

Authors: Dmitri Martila
Category: Relativity and Cosmology

[102] viXra:2402.0094 submitted on 2024-02-18 20:04:47 , (212 unique-IP downloads)

Euler-Mascheroni Constant is Irrrational

Authors: Dmitri Martila
Category: Number Theory

[101] viXra:2402.0092 submitted on 2024-02-18 11:11:18 , (251 unique-IP downloads)

Proof of Riemann Hypothesis via Robin's Theorem

Authors: Dmitri Martila
Category: Number Theory

[100] viXra:2402.0091 submitted on 2024-02-18 11:13:59 , (173 unique-IP downloads)

The Signature of Abc Conjecture is Proven

Authors: Dmitri Martila
Category: Number Theory

[99] viXra:2402.0090 submitted on 2024-02-18 12:04:49 , (159 unique-IP downloads)

An Attempt to Prove the Riemann Hypothesis Simply

Authors: Dmitri Martila
Category: Number Theory

[98] viXra:2402.0089 submitted on 2024-02-18 12:07:06 , (158 unique-IP downloads)

Proof of Some Conjectures and Riemann Hypothesis

Authors: Dmitri Martila
Category: Number Theory

[97] viXra:2402.0087 submitted on 2024-02-18 19:16:34 , (145 unique-IP downloads)

Proof of Strong Golbach Conjecture

Authors: Dmitri Martila
Category: Number Theory

[96] viXra:2305.0136 submitted on 2023-05-20 00:42:27 , (211 unique-IP downloads)

Proofs of ABC Conjecture

Authors: Dmitri Martila
Category: Number Theory

[95] viXra:2305.0058 submitted on 2023-05-06 03:17:18 , (181 unique-IP downloads)

Problem with the Derivation of Navier-Stokes Equations

Authors: Dmitri Martila
Category: Classical Physics

[94] viXra:2305.0031 replaced on 2023-05-18 10:35:24 , (408 unique-IP downloads)

Several Short Proofs of the Riemann Hypothesis

Authors: Dmitri Martila
Category: Quantum Physics

[93] viXra:2107.0139 submitted on 2021-07-23 19:03:14, (198 unique-IP downloads)

Is the Gravity-matter System Time-reversible?

Authors: Dmitri Martila
Category: Astrophysics

[92] viXra:2107.0137 submitted on 2021-07-23 19:04:08, (250 unique-IP downloads)

Acceptable Facts Point to Validity of Riemann Hypothesis

Authors: Dmitri Martila
Category: Number Theory

[91] viXra:2105.0137 submitted on 2021-05-23 10:41:56, (178 unique-IP downloads)

One Can not Observe the Impact with Detector the Zero Cross-Section Dark Matter Particle: it is Invisible Matter

Authors: Dmitri Martila
Category: General Science and Philosophy

[90] viXra:2105.0073 submitted on 2021-05-13 15:10:39, (371 unique-IP downloads)

Disproof of Riemann Hypothesis

Authors: Dmitri Martila
Category: Number Theory

[89] viXra:2104.0152 replaced on 2021-05-18 07:23:13, (318 unique-IP downloads)

Is Our World an Intelligent Simulation?

Authors: Dmitri Martila
Category: General Science and Philosophy

[88] viXra:2104.0151 submitted on 2021-04-25 10:08:16, (183 unique-IP downloads)

Natural Boundaries

Authors: Dmitri Martila
Category: General Science and Philosophy

[87] viXra:2104.0004 submitted on 2021-04-02 20:59:35, (313 unique-IP downloads)

Black Hole Is Hole Which Is Black

Authors: Dmitri Martila
Category: Astrophysics

[86] viXra:2103.0180 submitted on 2021-03-28 07:53:38, (199 unique-IP downloads)

Going to the Root of Quantum Measurement Problem

Authors: Dmitri Martila
Category: Quantum Physics

[85] viXra:2103.0133 replaced on 2021-04-11 14:59:17, (550 unique-IP downloads)

Simulation Hypothesis and Dark Matter

Authors: Dmitri Martila
Category: Astrophysics

[84] viXra:2101.0111 submitted on 2021-01-16 13:40:09, (235 unique-IP downloads)

Toward Advances in Medicine and Interstellar Travel

Authors: Dmitri Martila
Category: Astrophysics

[83] viXra:2012.0192 submitted on 2020-12-25 16:54:02, (245 unique-IP downloads)

Why did Nature need Quantum Mechanics at all?

Authors: Dmitri Martila
Category: Quantum Physics

[82] viXra:2012.0086 replaced on 2021-07-23 21:21:05, (650 unique-IP downloads)

Proof of the ABC Conjecture

Authors: Dmitri Martila
Category: Number Theory

[81] viXra:2012.0054 submitted on 2020-12-08 20:04:57, (276 unique-IP downloads)

What Atheist Steven Hawking Has Discovered at All, if Black Holes Do Not Evaporate?

Authors: Dmitri Martila
Category: Astrophysics

[80] viXra:2011.0199 replaced on 2021-03-24 06:29:36, (282 unique-IP downloads)

Acknowledgment of Non-linearity or How to Solve Several Conjectures

Authors: Dmitri Martila
Category: Number Theory

[79] viXra:2011.0198 replaced on 2021-03-24 08:56:39, (408 unique-IP downloads)

Exceptions from Robin's Inequality

Authors: Dmitri Martila
Category: Number Theory

[78] viXra:2011.0197 submitted on 2020-11-30 10:34:09, (426 unique-IP downloads)

Hawking Radiation by Neutron Stars

Authors: Dmitri Martila
Category: Astrophysics

[77] viXra:2011.0160 submitted on 2020-11-22 10:57:30, (417 unique-IP downloads)

There Are Questions with Hidden Answer, But Without a Way to Find the Answer

Authors: Dmitri Martila
Category: Set Theory and Logic

[76] viXra:2010.0239 submitted on 2020-10-30 11:05:12, (266 unique-IP downloads)

Can Both the Many Worlds and the Copenhagen Interpretation be True?

Authors: Dmitri Martila
Category: Quantum Physics

[75] viXra:2010.0108 submitted on 2020-10-15 20:19:42, (270 unique-IP downloads)

Argumenting the Validity of Riemann Hypothesis

Authors: Dmitri Martila
Category: Number Theory

[74] viXra:2010.0040 submitted on 2020-10-07 08:15:23, (442 unique-IP downloads)

Velocity of Human Dying: Does the Speed of Light Limit It?

Authors: Dmitri Martila
Category: Religion and Spiritualism

[73] viXra:2007.0116 submitted on 2020-07-15 00:59:51, (406 unique-IP downloads)

Riemann Hypothesis: New Criterion, Evidence, and One-Page Proof

Authors: Dmitri Martila
Category: Number Theory

[72] viXra:2007.0115 replaced on 2021-07-27 18:49:17, (297 unique-IP downloads)

Proofs for Goldbach's, Twin Prime, and Polignac's Conjectures

Authors: Dmitri Martila
Category: Number Theory

[71] viXra:2007.0114 submitted on 2020-07-15 01:04:48, (181 unique-IP downloads)

One-Page Refutation of Abc-Conjecture

Authors: Dmitri Martila
Category: Number Theory

[70] viXra:2007.0113 submitted on 2020-07-15 01:07:12, (1075 unique-IP downloads)

A More Elegant Proof of Poincare Conjecture

Authors: Dmitri Martila
Category: Topology

[69] viXra:2007.0112 submitted on 2020-07-15 01:11:33, (201 unique-IP downloads)

Gravity Law Without Universalism is Solving Many Tasks

Authors: Dmitri Martila
Category: Relativity and Cosmology

[68] viXra:2006.0082 submitted on 2020-06-09 13:28:00, (190 unique-IP downloads)

One Page Refutation of Theory of Relativity of Einstein

Authors: Dmitri Martila
Category: Relativity and Cosmology

[67] viXra:2005.0282 replaced on 2020-06-09 00:40:32, (355 unique-IP downloads)

A New Criterion for Riemann Hypothesis or a True Proof?

Authors: Dmitri Martila
Category: Number Theory

[66] viXra:2005.0258 replaced on 2020-05-27 23:02:24, (424 unique-IP downloads)

One page Proof of Riemann Hypothesis

Authors: Dmitri Martila
Category: Number Theory

[65] viXra:2005.0256 submitted on 2020-05-27 12:00:03, (322 unique-IP downloads)

Newton's Limit Operator Has no Sense

Authors: Dmitri Martila
Category: Functions and Analysis

[64] viXra:2005.0209 replaced on 2020-05-22 07:10:26, (701 unique-IP downloads)

Wiles Has not Proven the Fermat’s Last Theorem

Authors: Dmitri Martila
Category: Algebra

[63] viXra:2005.0187 submitted on 2020-05-18 10:06:05, (276 unique-IP downloads)

First Incompleteness Theorem New Way of Proving

Authors: Dmitri Martila
Category: Set Theory and Logic

[62] viXra:2004.0613 replaced on 2020-05-27 09:05:23, (418 unique-IP downloads)

Mond Solves All Problems

Authors: Dmitri Martila
Category: Relativity and Cosmology

[61] viXra:2003.0028 submitted on 2020-03-01 11:12:03, (156 unique-IP downloads)

Mass of Proton in Quantum Gravity

Authors: Dmitri Martila
Category: Quantum Gravity and String Theory

[60] viXra:2002.0202 submitted on 2020-02-10 08:24:07, (186 unique-IP downloads)

The Possibility to Explain Dark Matter Without Need of Actual Matter is Still Open

Authors: Dmitri Martila
Category: Astrophysics

[59] viXra:2002.0144 replaced on 2020-02-09 05:35:03, (527 unique-IP downloads)

The God is Proven in Theism, for there is Dogma of His Existence

Authors: Dmitri Martila
Category: Religion and Spiritualism

[58] viXra:2001.0701 replaced on 2020-04-12 01:16:03, (610 unique-IP downloads)

Is Mond Dead?

Authors: Dmitri Martila
Category: Relativity and Cosmology

[57] viXra:1912.0394 submitted on 2019-12-20 22:09:36, (195 unique-IP downloads)

Navier-Stokes Fluid Millennium Prize Problem

Authors: Dmitri Martila
Category: Astrophysics

[56] viXra:1912.0376 submitted on 2019-12-20 21:46:03, (192 unique-IP downloads)

Is Black Hole the hole?

Authors: Dmitri Martila
Category: Relativity and Cosmology

[55] viXra:1912.0359 submitted on 2019-12-19 03:14:38, (178 unique-IP downloads)

On Deviation Equation

Authors: Dmitri Martila
Category: Relativity and Cosmology

[54] viXra:1912.0352 submitted on 2019-12-18 08:45:02, (492 unique-IP downloads)

On Proofs of the Poincare Conjecture

Authors: Dmitri Martila
Category: Topology

[53] viXra:1911.0477 submitted on 2019-11-28 02:22:12, (236 unique-IP downloads)

Evidence, that X^2+y^3=1 and Others Have no Solution in Q>0

Authors: Dmitri Martila
Category: Number Theory

[52] viXra:1911.0437 submitted on 2019-11-25 08:59:37, (213 unique-IP downloads)

Impossibility of Gravitons and bi-Metric Gravity; Riemann Hypothesis Confirmed; Energy Localization Problem Solved; the Falsifiability of Science is Demonstrated

Authors: Dmitri Martila
Category: General Science and Philosophy

[51] viXra:1911.0425 replaced on 2019-12-18 08:06:34, (469 unique-IP downloads)

Dark Matter and Dark Energy Explained by Fix to Vanishing of Falling Matter

Authors: Dmitri Martila
Category: Astrophysics

[50] viXra:1911.0239 replaced on 2019-11-16 07:38:49, (235 unique-IP downloads)

Solution to the New Paradox of Special Relativity

Authors: Dmitri Martila
Category: Relativity and Cosmology

[49] viXra:1908.0470 submitted on 2019-08-24 06:02:21, (388 unique-IP downloads)

Because Iniquity Shall Abound, the Love of Many Shall Wax Cold: Matthew 24:12

Authors: Dmitri Martila
Category: Religion and Spiritualism

[48] viXra:1908.0253 submitted on 2019-08-12 23:49:23, (302 unique-IP downloads)

Please read this: Faith has Reasons

Authors: Dmitri Martila
Category: Religion and Spiritualism

[47] viXra:1907.0398 replaced on 2019-08-09 12:34:51, (339 unique-IP downloads)

Energy-Momentum is not Defined Globally, But Locally

Authors: Dmitri Martila
Category: Mathematical Physics

[46] viXra:1806.0241 submitted on 2018-06-17 14:07:34, (283 unique-IP downloads)

The Jesus is Like the Perfect Mirror for the Souls

Authors: Dmitri Martila
Category: Religion and Spiritualism

[45] viXra:1805.0048 replaced on 2018-05-03 01:34:21, (310 unique-IP downloads)

Introducing Light Force

Authors: Dmitri Martila
Category: Classical Physics

[44] viXra:1803.0025 submitted on 2018-03-01 08:43:28, (210 unique-IP downloads)

Is GR Right?

Authors: Dmitri Martila
Category: Relativity and Cosmology

[43] viXra:1803.0006 submitted on 2018-03-02 01:45:47, (171 unique-IP downloads)

Is Einstein GR Descredited by Dark Matter and Big Bang and Black Holes?

Authors: Dmitri Martila
Category: Relativity and Cosmology

[42] viXra:1802.0220 submitted on 2018-02-18 07:17:31, (123 unique-IP downloads)

On the Energy Commutators in Quantum Mechanics

Authors: Dmitri Martila
Category: Quantum Physics

[41] viXra:1712.0566 replaced on 2019-12-20 12:01:56, (303 unique-IP downloads)

Navier Stockes Equation, Integrals of Motion and Generalization of the Equation of Continuity of the Flow of Matter to the Theory of Relativity

Authors: Dmitri Martila
Category: Condensed Matter

[40] viXra:1711.0272 submitted on 2017-11-10 13:59:02, (1136 unique-IP downloads)

Do Stokes' and Gauss's Theorems Hold in Curved Spacetime?

Authors: Dmitri Martila
Category: Mathematical Physics

[39] viXra:1710.0118 submitted on 2017-10-10 23:07:27, (502 unique-IP downloads)

Is it so Hard to Prove the Poincare Conjecture?

Authors: Dmitri Martila
Category: Topology

[38] viXra:1710.0035 submitted on 2017-10-04 01:50:21, (2002 unique-IP downloads)

The Statistical Proof of the Riemann Hypothesis

Authors: Dmitri Martila
Category: Set Theory and Logic

[37] viXra:1707.0287 submitted on 2017-07-21 14:03:43, (248 unique-IP downloads)

The Optimal Web of Interconnected Human Intellects

Authors: Dmitri Martila
Category: General Mathematics

[36] viXra:1705.0103 submitted on 2017-05-04 08:01:49, (141 unique-IP downloads)

To the Map of Science and the Quantum Physics Consistency

Authors: Dmitri Martila
Category: Quantum Physics

[35] viXra:1607.0171 submitted on 2016-07-14 11:40:51, (261 unique-IP downloads)

The David Bohm Pilot-Wave Interpretation is the Best Approach to Reality of Quantum Physics

Authors: Dmitri Martila
Category: Quantum Physics

[34] viXra:1607.0097 replaced on 2016-07-11 11:23:09, (532 unique-IP downloads)

Not Disproved Solutions to Millennium Prize Problems

Authors: Dmitri Martila
Category: General Mathematics

[33] viXra:1605.0174 replaced on 2016-05-22 08:43:02, (313 unique-IP downloads)

To Donald Trump: the Holy Mom and Sin-Drunk World, the Smarter One Is?

Authors: Dmitri Martila
Category: General Science and Philosophy

[32] viXra:1512.0348 replaced on 2016-01-23 03:18:08, (384 unique-IP downloads)

Dark Matter and Weak Field Limit of General Relativity

Authors: Dmitri Martila
Category: Astrophysics

[31] viXra:1512.0347 submitted on 2015-12-17 06:17:45, (172 unique-IP downloads)

The Matter in Fixed Spacetime: Dark Matter Mystery is Solved

Authors: Dmitri Martila
Category: Relativity and Cosmology

[30] viXra:1512.0346 submitted on 2015-12-17 06:22:00, (137 unique-IP downloads)

Stuck Metrology Meter Into Black Hole: Joy and Excitement

Authors: Dmitri Martila
Category: Relativity and Cosmology

[29] viXra:1510.0329 replaced on 2015-10-23 01:38:57, (308 unique-IP downloads)

Is the Energy of Universe Above the Zero?!

Authors: Dmitri Martila
Category: Relativity and Cosmology

[28] viXra:1510.0057 submitted on 2015-10-06 03:47:10, (1485 unique-IP downloads)

Clearest Proof of Poincare Conjecture or Is Grisha Perelman Right?

Authors: Dmitri Martila
Category: Topology

[27] viXra:1510.0019 submitted on 2015-10-02 11:31:49, (365 unique-IP downloads)

Is Atheism Evil?

Authors: Dmitri Martila
Category: Religion and Spiritualism

[26] viXra:1509.0269 submitted on 2015-09-28 09:55:51, (233 unique-IP downloads)

Has the Joke "Spaghetti Monster" a Deeper Meaning for Atheism?

Authors: Dmitri Martila
Category: Mind Science

[25] viXra:1509.0209 replaced on 2015-09-24 00:55:35, (462 unique-IP downloads)

On the Millennium Prize Problems

Authors: Dmitri Martila
Category: General Science and Philosophy

[24] viXra:1509.0192 replaced on 2015-09-25 14:19:42, (405 unique-IP downloads)

Standards Are Good for Clearing Science

Authors: Dmitri Martila
Category: Social Science

[23] viXra:1507.0152 submitted on 2015-07-20 04:14:59, (246 unique-IP downloads)

In God We Mind or Physical Considerations of Divine

Authors: Dmitri Martila
Category: General Science and Philosophy

[22] viXra:1507.0114 submitted on 2015-07-15 11:00:10, (338 unique-IP downloads)

My Proofs of God

Authors: Dmitri Martila
Category: General Science and Philosophy

[21] viXra:1507.0015 submitted on 2015-07-02 07:25:19, (243 unique-IP downloads)

The Incompleteness of Universe

Authors: Dmitri Martila
Category: Relativity and Cosmology

[20] viXra:1507.0005 submitted on 2015-07-01 03:40:35, (270 unique-IP downloads)

The Ultimate Modification of Einstein's Gravity

Authors: Dmitri Martila
Category: Relativity and Cosmology

[19] viXra:1504.0194 submitted on 2015-04-25 05:11:40, (169 unique-IP downloads)

Derivation of Eq.(3) in Bell's Historical Paper Fails?

Authors: Dmitri Martila
Category: Quantum Physics

[18] viXra:1504.0103 submitted on 2015-04-14 04:56:09, (235 unique-IP downloads)

Black Holes in Collider? not Really.

Authors: Dmitri Martila
Category: High Energy Particle Physics

[17] viXra:1503.0103 replaced on 2015-03-16 13:42:20, (349 unique-IP downloads)

Consistent Faith of a Physicist: God's Grace Within Physics

Authors: Dmitri Martila
Category: History and Philosophy of Physics

[16] viXra:1502.0223 replaced on 2015-03-02 01:50:28, (376 unique-IP downloads)

On value of David Bohm’s Quantum Mechanics

Authors: Dmitri Martila
Category: Quantum Physics

[15] viXra:1502.0160 submitted on 2015-02-18 20:01:29, (327 unique-IP downloads)

History of Problem, Cooperstock is Wrong.

Authors: Dmitri Martila
Category: General Science and Philosophy

[14] viXra:1502.0082 replaced on 2015-02-22 06:59:32, (619 unique-IP downloads)

Cooperstock is Wrong: the Dark Matter is Necessary

Authors: Dmitri Martila
Category: Astrophysics

[13] viXra:1412.0151 replaced on 2015-02-08 10:13:16, (341 unique-IP downloads)

Moving Into Black Hole: is there a Wall?

Authors: Dmitri Martila
Category: Relativity and Cosmology

[12] viXra:1412.0138 submitted on 2014-12-07 13:34:35, (179 unique-IP downloads)

Bat Catches Fly in Schwarzschild Spacetime

Authors: Dmitri Martila
Category: Relativity and Cosmology

[11] viXra:1411.0218 replaced on 2014-11-23 10:34:38, (334 unique-IP downloads)

Faith in God and the Light on the Paradoxes of Einstein

Authors: Dmitri Martila
Category: Relativity and Cosmology

[10] viXra:1410.0182 submitted on 2014-10-28 05:46:57, (286 unique-IP downloads)

Comment on ``backreaction of Hawking Radiation on a Gravitationally Collapsing Star I: Black Holes?''

Authors: Dmitri Martila
Category: Relativity and Cosmology

[9] viXra:1410.0086 submitted on 2014-10-16 12:17:13, (321 unique-IP downloads)

Reply to "Phantom Energy and Cosmic Doomsday"

Authors: Dmitri Martila
Category: Relativity and Cosmology

[8] viXra:1409.0177 replaced on 2014-10-26 14:05:24, (314 unique-IP downloads)

Can Niels Bohr's Philosophy be Wrong?

Authors: Dmitri Martila
Category: Quantum Gravity and String Theory

[7] viXra:1407.0035 replaced on 2014-11-04 08:53:06, (698 unique-IP downloads)

Collection of Arguments Vs. Niels Bohr's Destruction of Reality

Authors: Dmitri Martila
Category: Quantum Physics

[6] viXra:1311.0059 submitted on 2013-11-09 05:09:59, (3046 unique-IP downloads)

Only Simply Connected Space is Homeomorphic to Sphere

Authors: Dmitri Martila
Category: Topology

[5] viXra:1311.0048 submitted on 2013-11-07 04:41:30, (463 unique-IP downloads)

Simplest Explanation of Dark Matter and Dark Energy

Authors: Dmitri Martila
Category: Relativity and Cosmology

[4] viXra:1311.0045 submitted on 2013-11-06 08:00:28, (441 unique-IP downloads)

Entropy of Real Pendulum

Authors: Dmitri Martila
Category: Mathematical Physics

[3] viXra:1306.0012 submitted on 2013-06-04 04:33:13, (235 unique-IP downloads)

Moller Formula Fails the Experimental Test

Authors: Dmitri Martila
Category: Relativity and Cosmology

[2] viXra:1305.0131 submitted on 2013-05-21 06:50:47, (287 unique-IP downloads)

Three Ethers of Einstein

Authors: Dmitri Martila
Category: Relativity and Cosmology

[1] viXra:1304.0086 replaced on 2013-04-26 11:07:51, (416 unique-IP downloads)

Flux Divergence Method of Solving Einstein Equations

Authors: Dmitri Martila
Category: Relativity and Cosmology